Proceedings of the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019)

In this study, the correlation of human physiological parameters to ambient temperature was evaluated in the temperature range of 21–29 °C. The physiological parameters investigated herein included mean skin temperature (MST), heart rate, the ratio of absolute power in low frequency (LF) and high frequency (HF) bands (LF/HF ratio). The results of ANOVA and R test indicated that MST was correlated to ambient temperature, while LF/HF ratio was not found to be correlated at all. Heart rate was a little more correlate to low temperature than high temperature. The conclusions are significant to select suitable parameters for human thermal response research in the moderate thermal environment.

Tents, generally used as temporary shelters, have been neglected in architectural design for long. No designer cares about the living environment inside the tent because nobody is willing to choose it as a permanent residence. However, in Sichuan Province, China, many Tibetan herdsmen, whose business is still pasturing cattle, have to live a hard life for decades in traditional cow-hair-felt tents. They always suffer from kind of diseases because of the terrible environment inside the tent. To raise the living standard of Tibetan herdsmen, some new nomadic tents have been developed based on the concept of Integrated Design Process of green building design. This paper introduces the research achievement of new nomadic tents for Tibetan herdsmen. Factors involved in the design of the new tents for nomadic life such as thermal properties, supporting system, ventilation, and vernacular culture have been investigated systematically. Combination of different varies related to ventilation also have been tested to discover the most important one. An index named Ratio of Clerestory to Envelopment (RCE) has been suggested to evaluate the effect of natural ventilation inside the tent. Now the new nomadic tents have been accepted by Tibetan herdsmen as an ideal residence to their daily life.

Traditional air-conditioning control system assumes indoor air temperature to be uniformly distributed. However, indoor air is often not completely well-mixed. The air temperature and speed data obtained from sensors cannot represent thermal state of the whole room. This paper aims to investigate real thermal perception of the occupants in an air-conditioned office model. A Computational Fluid Dynamics (CFD) based method is utilised for building modelling. The temperature and air speed calibrations are adopted to offset the temperature and air speed difference between the actual sensors (i.e. temperature and speed sensors) and the virtual sensors (i.e. temperature and speed sensors) located in the occupied zone. Predicted Mean Vote (PMV) method is employed to evaluate the thermal comfort performance under different indoor air conditions. Simulation results show that indoor thermal comfort performance in a specified office model is well improved by calibrating the differences between the actual and virtual temperature sensors.

The smoke generated from the process of welding exerts an extremely large harmful effect on the health of workers. Previous studies have shown that the requirement of good indoor air quality within the workshop cannot be guaranteed by natural ventilation system. The auxiliary mechanical ventilation and dust removal system is needed in this situation. This study investigates the performance of the system of this kind based on numerical simulation. It mainly studies the influence of different air change rates on the air distribution and the dust removal efficiency of the welding plant with push–pull ventilation and dust removal system. Results show that the value of air change rate should be considered at least 5.5 times per hour. This study provides the reference for the application of mechanical ventilation and dust removal system in welding plant.

Currently, the insufficiency of dependable data and regional differences hinders reliable evaluation of phthalate esters (PAEs). In this study, a total of 10 households with schoolchildren were selected for field measurement and 40 dust samples were collected and measured during autumn and winter in Changsha, China. The results showed that the most frequently detected compounds of PAEs were di(2-ethylhexyl)phthalate (DEHP) with detection frequency of 100% and dibutyl phthalate (DBP). The concentrations of DEHP and DBP displayed difference between autumn and winter. However, the difference was not statistically significant. The children’s daily inhalation of PAEs from household dust by mouth was 400 times that by skin exposure. The cancerogenic risk caused by DEHP exposure for children was 0.5 × 10−6–29.8 × 10−6 with an average of 7.62 × 10−6. It was 7.6 times that stipulated by USEPA. This study provided reliable data of PAEs in house dust in different areas of China.

In modern industry, workers in factories are mostly engaged in maintenance, welding, assembling and other physical activities with higher metabolic rate than office works. The evaluation of thermal environment with such physical activity is important for the welfare of workers and enhancing their working efficiency. With the increase of physical activity, the metabolism and heat production of human body will increase, which is often accompanied by sweat regulation. The amount of sweat is an important factor in calculating the evaporative heat loss of the human body, as well as an important component of the thermal balance of human body. In this study, experiments were carried out to test people’s sweat rate using sweat absorption paper. All subjects were Chinese college students. The air temperatures during experiments were 26, 28 and 30 °C. Metabolic rate, mean skin temperature and ear-canal temperature were tested. Subjects took three activities of sitting and carry heavy box with two different weights. The tested mean metabolic rates for three activities were 1.18 met, 1.7 met and 2.73 met. The results show that sweat rate will increase as metabolic rate and air temperature increases. With increase of activity level, mean skin temperature showed a tendency to increase first and then decrease. This was caused by increased sweat and evaporative heat. Sweat rate model was deduced based on maximum evaporative heat and required evaporative heat. Compared to the original Shapiro prediction equation and the piecewise equation, the new model predicts sweat rate more accurately.

Benzene, toluene, ethylbenzene and xylenes (BTEX) lead to cabin air pollution, which is harmful to passengers and drivers. In order to decrease the harm, the BTEX attenuation with time is analyzed by monitoring the BTEX concentrations in 38 vehicles with Air Sampler and Gas Chromatograph and by the curve estimation regression with the SPSS statistical software. Results show that the optimum attenuation curve between the BTEX pollution (y) and time (x) is a cubic equation with one variable, in which $$y_{\text{benzene}} = {-}0.004x^{3} + 0.228x^{2} {-}5.787x + 130.803$$, $$y_{\text{toluene}} = {-}0.007x^{3} + 0.451x^{2} {-}12.510x + 326.425$$, $$y_{\text{ethyl benzene}} = {-}0.003x^{3} + 0.212x^{2} {-}5.345x + 118.780$$ and $$y_{\text{xylenes}} = {-}0.008x^{3} + 0.505x^{2} {-}12.777x + 289.001$$. When the BTEX pollution is zero, the attenuation time is 3.4–4.2 years. The BTEX diffusion from in-vehicle materials can last for several years so that the BTEX attenuation and control is a long-term process.

This study presents the flow trajectory, pollutant distribution of vortex ventilation with different pollutant source locations. It turns out that due to pressure gradient of column vortex, the pollutant can be inhaled by the vortex after releasing when the sources are in the vortex zone. Meanwhile, due to the obvious tangential velocity and radial velocity of the column vortex, the flow trajectory of pollutant in vortex ventilation is close to a logarithmic spiral, which means that the farther the pollutant source from the vortex center, the longer the path of pollutant is, and the larger the pollution range is. The results indicate that the pollutant source should be in the range of vortex zone in the design, and it will reach the best performance when the pollutant source is just near the vortex core.

The underfloor air distribution (UFAD) system is widely used in the data center account for the potential of energy saving. However, the uneven distribution of airflow in the underfloor plenum will deteriorate the thermal environment of UFAD system and cause the uniform cooling for servers in the racks. To improve the cooling performance of UFAD system based data center, several kinds of underfloor vertical baffles (UVB) were designed and employed to guide airflow path. By using the computational fluid dynamics (CFD) model, the thermal environment of UFAD based data center had been significantly improved. The results show that the maximum temperature at the top of racks was reduced by about 8.5 °C by deploying the enclosed baffles. The average values of average inlet/outlet temperature were decreased by 4.15 and 3.03 °C, respectively, and the standard deviations of them were 8.8 and 19.3% of those in no-baffle model.

The air conditioning in data center should be running in cold mode throughout the year account for amount of heat released in a relatively small space of rack. However, most of the heat in data center is released from electronic chips. Thus, the energy consumption of air conditioning will be significantly decreased if the heat released by electronic chips can be mitigated directly. Compared to the air cooling heat sink (ACHS), the cooling performance of liquid cooling heat sink (LCHS) is dramatically improved as it can remove more heat from the surface of electronic chip quickly. To further improve the cooling performance of LCHS, the effects of channel deployment are investigated in a commonly used S-shaped LCHS in this study. The numerical simulation results show that the average surface temperature of electronic chip can be reduced by 22.91 °C while the number of channels is increased from one to five.

There is a growing concern over whether ventilation rates (VRs) for building are health-based. For example, moisture-related problems, e.g., molds and mites, can pose adverse health effects on occupants. However, ventilation-induced moist indoors is an overlooked issue in China. In this paper, the effects of VRs, as well as typical building characteristics, on indoor humidity levels were investigated using EnergyPlus. 1008 residential models (with low infiltration, and various ventilation and climate scenarios) were simulated. Generally-agreed non-healthy humidity levels were used to analyze health risks. The results showed that, first, buildings in two hot summer zones were at risk of high indoor humidity, while buildings in two cold zones might experience higher risks of low humidity. Second, higher the VRs, higher the risk of low humidity in cold zones, and higher the risk of dampness in hot summer zones. Third, it can be easier to be more humid indoors for small-size, top-floor, or north orientation residences in China.

Impinging jets with high temperature can be commonly found among industrial applications, such as exhaust gas from turbine engines that used for ships, heavy trucks or aircrafts. When the heating source is in a confined space, i.e., a garage or a machine room, additional cooling method, e.g., spray cooling, usually needs to be applied to decrease the temperature of the impinging jet, to minimize damages to the interior structure. In this paper, numerical simulation is used to study the cooling effect of water spray on an impinging jet at ~800 K. The confined space also incorporates an exhaust fan to remove the generated gas. The cooling effect of both local cooling (i.e., directly spraying at the heat source) and large-area cooling (i.e., spraying spread out the whole space) are investigated. Six cases were designed. In the first case, there were no nozzles were set. In the next 5 cases, the total number of nozzles were 65 and remained unchanged, by changing the number of nozzles used for larger-area cooling and local cooling, the cooling effect of different installation scheme of nozzles was obtained thorough computational method. For all the cases, the flow rate of the flue gas is 28.0 kg/s, and hourly water consumption of each nozzle is ~0.8 m3/h. The results show that increasing the number of nozzles that used for local cooling result in a better cooling effect, but the increment of cooling effect will be slightly when the number of local cooling nozzles up to ~20.

Formaldehyde is a harmful gaseous pollutant with proved adverse health effects. In this study, the correlation between long-term indoor formaldehyde concentration and decay pattern of the emission sources was analyzed mathematically. They shared a same decay pattern. A total of 30 series of long-term concentration data of formaldehyde had been collected from literature. The one-exponential empirical model describes well on the long-term variation patterns of indoor concentration and pollutant load. The decay constant varies within two magnitudes (10−6 h−1–10−4 h−1) and log-normally distributed, of which μ is −9.01 and σ is 0.89. The estimated decay constant is helpful in the pollutant load and concentration estimation in other occasions.

Secondary school classrooms in North China mostly use centralized heat supply or split air-conditioning in winter. Due to the long-term closure of the classroom doors and windows, indoor air quality reduces the learning efficiency of students. Taking a classroom in a secondary school in Jinan as an example, this paper gives a one-week monitoring of indoor and outdoor air and gives changes in indoor and outdoor CO2 concentration, PM2.5 concentration, temperature, and relative humidity. This paper also provides basic data for the determination of fresh air volume in classrooms under haze conditions.

Indoor thermal comfort of the human body under different environments was studied in this paper using heart rate variability (HRV) analysis. Six male subjects with similar physical characteristics were recruited in the experiment. And electrocardiogram (ECG) data of subjects were recorded continuously in an environmental chamber. Thereafter, the HRV indices were obtained using frequency-domain method, among which we selected the ratio of the low-frequency power and high-frequency power (LF/HF) as an indicator to evaluate the thermal comfort in the study. Meanwhile, questionnaire surveys about thermal comfort and thermal sensation were carried out to obtain the subjective thermal comfort scores of these subjects under various environments. Relationships between mean LF/HF values and mean thermal comfort scores were analyzed based on the experimental and survey data. Results showed the LF/HF was linearly correlated with thermal comfort and thermal sensation scores. Furthermore, higher LF/HF values yielded thermal discomfort, but lower LF/HF values might indicate thermal comfort of the human body.

According to the measured data of Shenyang typical street valley, the spatial distribution characteristics of inhalable particles in Shenyang and their correlation with wind speed, temperature, and traffic flow are analyzed by using the Origin software. The daytime variation and spatial distribution of pollutant concentration in street valley were studied. The relationship between vehicle flow and pollutant concentration and the influence on street atmosphere were obtained. Under the measured conditions, the distribution of pollutants in the street canyons is affected by the diurnal variation of pollutant mass concentration, peak and valley values and other factors. The conditions in the street canyon particulate pollutant mass concentration are mainly influenced by two factors: one is the change of background mass concentration; the other is a cumulative emissions from motor vehicles in the street canyon. However, the diurnal variation of pollutant mass concentration in the street was similar to that of background mass concentration, and there was no visual correlation with traffic flow. The effect of greening trees on the distribution and diffusion of pollutants in the valley of urban street is more complex. The greening tress has certain adsorption effect on the particulate matter, but it can also prevent the pollutant from spreading outside the mass concentration of pollutants in the street valley.

Air filters are one effective way of removing indoor fine particulate matter (generally known as PM2.5). An accurate evaluation of indoor PM2.5 filtration load will provide great help in designing efficient air filtration systems. In order to make the existing indoor PM2.5 filtration load calculation model more available by considering the availability of some important parameters, such as air infiltration volume through a unit length of external window (ql), particle penetration factor (P), and deposition rate (k), this study introduces a determination method of those key design parameters for various external window airtightness levels under infiltration conditions. Furthermore, the indoor PM2.5 filtration loads were quantified based on a longitudinal field measurement from five unoccupied offices located in the central area of Beijing, China. Results revealed that higher airtightness level windows can help to significantly decrease the indoor PM2.5 filtration load. The proposed method in this study can help in the calculation of indoor PM2.5 filtration load through infiltration and the design of indoor air filtration systems.

Indoor chemical reaction is one important factor impacting indoor air quality. Considering the influence of chemical reaction between ozone and human body surface, it is the premise for controlling ozone pollution and improving indoor air quality by obtaining the features of indoor combined pollution induced by ozone. Firstly, based on the method of experimental research, this study analyzed the variation characteristics of ozone and total volatile organic compounds’ pollution under three ventilation modes of mixing, displacement, and floor orifice. Secondly, by means of numerical simulation, this study focused on the chemical reaction between ozone (O3) and terpenes under the condition of residential variable density and analyzed the unsteady change characteristics of the concentration of air chemical reaction products under the conditions of mixed and displacement ventilation modes and different air changes. The results show that the concentration of pollutants is negatively correlated with the number of air changes under the same ventilation mode. At the same time, the concentration of total volatile organic compounds (TVOC) follows the ozone concentration obviously. In addition, the amount of O3 in the room determines the process and degree of the whole air chemical reaction. The concentration of reaction product under mixed ventilation is lower than that under displacement ventilation.

Air filters have been widely used in the protection of production and living environments. The dynamic pressure drop of the air filter directly affects the energy consumption of the ventilation system, which has caused widespread concern. This chapter focused on theoretical modelling of dust cake resistance and proposed the device and methods for accurately measuring porosity. Based on the analysis of Cunningham’s sliding correction coefficient, the surface filtration resistance model of lognormally distributed particles is derived and simplified into monodispersed form. A laser scanning distance-measuring device was built to measure the thickness of the dust layer and its variation on the surface of the PTFE membrane. Finally, the porosity of the dust cake was measured and compared with the previous studies.

It is significant for the removal of environmental pollutants if a glass which is widely used in daily life has photocatalysis. In this study, different types of photocatalytic glass are prepared by coating with a nano-composite film. This N-F-TiO2/rGO (TGNF) film is made by compositing TiO2 doped with N and F ions (N-F-TiO2) and the reduced graphene (rGO) via sol-gel method. Then the glass with TGNF film is characterized by XRD, AFM, and UV-Vis. The visible-light photocatalytic activity of the composite materials is evaluated by the degradation of methylene blue aqueous solution, a typical organic pollutant, to study the effects of fluorine doping amount on the properties of the materials. The experimental results are as follows: (1) The degradation efficiency of the glass coated with TGNF film is greater than that with TiO2 doped with N and the composite of N-TiO2 and rGO; (2) The optical absorption of the glass coated with TGNF film is super-strong in the visible light region from 380 to 800 nm; (3) The TGNF film added with 9% F ions and calcined at 400 °C has the highest photocatalytic efficiency and relatively optimal transmission.

This study analyzed the influence of rural residential spatial layout and building envelope on indoor thermal environment in northern Guangxi and put forward some feasible suggestions for improving the indoor thermal environment of existing rural dwellings. To achieve these goals, the field surveys have been carried out on two typical rural dwellings, wooden dwellings, and brick-concrete dwellings, by measuring thermal environment parameters, including indoor and outdoor air temperature, relative humidity, air velocity, solar radiation intensity, and globe temperature. The results showed that the average outdoor air temperature was 11.8 °C and 81.5% represented the average relative humidity level, which was very cold and moist in winter. The adverse weather conditions in winter and the poor airtightness and moisture resistance of building envelope led to the uncomfortable living environment. The indoor maximum temperature was lower than 12.0 °C in winter while the indoor relative humidity was higher than 70.0% without heating system. Considering the characteristics of the building envelope and the current situation of indoor and outdoor thermal environment in this area, it was suggested that the airtightness of the building envelope be improved. Meanwhile, it was also recommended that effective moisture-proof measures should be added to improve the thermal insulation and humidity reduction of residential dwellings in winter.

The diffusion coefficient (D), partition coefficient (K), and initial emittable concentration (C0) are three key parameters to characterize the volatile organic compound (VOC) emissions of building materials. It is important to determine the accurate VOC emission characteristic parameters for evaluating indoor air quality and selecting appropriate control strategies. In this paper, a fast and accurate airtight chamber method was proposed for determining the VOC emission characteristic parameters. Through deriving the relationship between the characteristic parameters, the fully explicit analytical solution for the VOC concentration in the airtight chamber was expressed as a correlation of K. Based on the normalized relative sensitivity coefficient, the experimental data of gas-phase VOC concentration in the airtight chamber were fitted nonlinearly, and the values of the emission characteristic parameters were obtained. In addition, this new method was validated and compared with a well-recognized experimental method, and showed advantages in efficiency, accuracy and operation convenience.

A mixing ventilation (MV) system integrated with a chilled ceiling (CC) cooling system will be a potential advanced heating, ventilation and air conditioning (HVAC) system in the modern office buildings. In this paper, an experimental study of the air distribution characteristics in a room with MV and CC was performed when considering the effect of the heat transfer of external envelope. The distributions of indoor air temperature and velocity were measured and evaluated by the vertical air temperature difference and turbulence intensity, respectively. The results showed that when chilled ceiling surface temperature ranged from 17.0 to 26.0 °C and supply air temperature was 16.0–22.0 °C, the increased trend of vertical air temperature was gradually switched to the decreased trend along the vertical direction, and the vertical air temperature differences in occupied zone were all not exceeded 0.4 °C. The average turbulence intensity was 30–41% when the internal and external sensible cooling loads equal 41.5 W/m2. The range of these evaluation indices varied clearly when the internal sensible cooling load increased from 41.5 to 69.5 W/m2, whereas they were almost the same when the external sensible cooling load increased from 41.5 to 69.5 W/m2.

With the acceleration of the aging society, the living environment quality for the elderly people has become the focus of the whole society. A lot of research shows that the thermal environment requirement and thermal adaptation behavior of the old people are different from those of young people. Based on the adaptation relationship between human being and building environment, a feedback loop system model of physiological, psychological and behavioral regulation of human adaptation to environment is established, and then a “four-layer skin” regulation mechanism is constructed. This paper also analyses the thermal adaptation behavior and stratified regulation strategies, and further prospects the research direction and focus in the field of thermal adaptation behavior and thermal environment regulation for the elderly people.

Conventionally, indoor temperature is non-uniformly distributed and it is important to predict the distribution of temperature when working space must be controlled. The prediction based on the linear superposition theorem in a fixed flow field is an alternative with consideration of both efficiency and accuracy. However, indoor temperature distribution is not clearly investigated when convective heat transfer from the building envelope exists since the indoor temperature is coupled with heat transfer process. In this study, a method is proposed to predict the indoor temperature distribution where convective heat transfer from the boundary exists based on superposition theorem. Two representative flow fields in the room, i.e., one for space-cooling and one for space-heating, are selected for comparison. The characteristics of the two flow fields are analyzed by using two factors k1 and k2. Results show that: (1) there is a linear relation between excess temperature distribution, excess supply air temperature and heat source intensity; (2) the steady temperature can be predicted fast and accurate once k1 and k2 are obtained through simulations of two arbitrary thermal cases; (3) The proposed method could predict the indoor temperature distribution with good accuracy compared with numerical method.

This paper attempts to answer the question whether there is any difference in indoor environmental perceptions between people with and without respiratory allergy. First, an online survey was conducted in China inquiring respondents’ sensitivity to changes in environmental factors including indoor air temperature, indoor relative humidity, indoor air freshness, and outdoor air pollution. Totally, 1293 persons from 30 provinces of China participated in the survey, including 478 allergics and 815 non-allergics. From this investigation over 70% of allergics reported themselves to be more sensitive to four respective environmental factors than others, which was statistically higher than the ratio of non-allergics. Secondly, published studies on environmental perceptions of allergics were reviewed. Ten studies were identified and their findings suggest that perception difference of thermal environment between allergics and non-allergics may occur when subjects are not thermally neutral while perception difference of air quality remains unclear. Therefore further research on this question is needed.

Taking an underground cave-dwelling in west area of Henan as the research object, based on a remote monitoring platform, a long-term thermal and humidity environment monitoring was carried out. A quantitative analysis showed that the indoor thermal environment adapted to local outdoor climate by passive techniques. Results show that a favorable micro-climate can be created by underground design. The ground air temperature varies from −12.9 to 38.7 °C. Compared to that, the courtyard air temperature fluctuates between −8.7 and 33.47 °C, which improved the outdoor thermal environment greatly. Selecting the upper north cave as the indoor analysis object, results show that the indoor air temperature is varying from 8.77 to 26.29 °C, and the relative humidity is fluctuating between 33% and 100. And 66.7% of the year is within the thermal comfort range. The annual thermal and humidity environment characteristics were analyzed quantitatively.

The intelligent perception system for the building environment is the crucial experimental platform and assessment system in the field of building environment studies. It is essential to establish a comprehensive real-time monitoring and evaluating platform that integrates building perception, and human perception, etc. for the study of the healthy residential environment. This paper further studies the methods for the establishment of a visualization platform of intelligent environmental perception that covers building perception and human perception. This platform collects the data based on the sensor module of terminal integration, takes the Internet of Things as the means of information exchange and communication, disposes and analyzes the data through software. This platform, characterized by real-time monitoring, wireless transmission, information processing, collaborative evaluation and information feedback, etc. has provided experimental methods and evaluation tools for the researches on the natural information induction of indoor building environment and the human demands for the indoor environment.

Current lab studies focus on forming a fixed environment for subjects and studying their thermal perceptions. A series of experiments were conducted to investigate occupants’ thermal perceptions and control behaviors over indoor environments. The obtained results showed that a too long or too short exposure urged subjects to more lower their ambient temperatures. With the warm exposure of 0 min without fans, i.e. subjects immediately lowered the indoor temperature when entering the experimental room, they had the largest desire to decrease indoor temperatures. Whether with or without fans, after being exposed to 30 °C for 10 min, subjects had the minimum requirements for lowering indoor temperatures. With the access to adjusting indoor temperatures, more than 90% of subjects changed indoor temperatures until they felt thermally neutral. And with fans, subjects finally chose higher temperatures. This study provides references for researches on occupants’ control behaviors and transient thermal comfort in real buildings.

Cooking is an important source of particulate matters (PM) in Chinese residences. Exposure to fine particles (PM2.5) in cooking oil fume (COF) emitted during cooking can lead to adverse health effects. Keeping the kitchen doors open might be conducive to improving air quality in kitchen, nonetheless, cooking activities would still elevate the particle concentrations by several folds from the background level both in kitchen and living room even with range hood on. This study investigated the control effect of intervention using computational fluid dynamics (CFD) simulations (PHOENICS). The boundary conditions were set up based on the calculation of multi-compartment flow model (CONTAM) for simplifying the CFD model. Two prevention measures, including configuring ceiling screen in kitchen to obstruct COF pervasion and employing air cleaner in living room to remove PM2.5, were simulated. Besides, cases of varied placement position of the ceiling screen and the air cleaner were compared as well. The results showed that setting ceiling screen could decrease PM2.5 concentration in living room by 0.7–10.4%, varying with quantity and position of ceiling screen. In comparison, the air quality in living room was much improved with an air cleaner, which enabled to approximately bring a 60–70% drop of PM2.5 concentration. This kind of research can help provide some guidance in engineering control strategies of air pollution due to residential cooking.

Chinese cooking methods can produce a large amount of hazardous cooking oil fume, which may include masses of organic carbon. This study collected PM2.5 samples of cooking emissions from five most common Chinese cooking methods (stir-, pan-, deep-frying, steaming, and boiling). Organic carbon (OC) and elemental carbon (EC) in PM2.5 were analyzed using the thermal/optical reflectance (TOR) method. Average second organic carbon (SOC) from different cooking methods was estimated via the method of minimum OC/EC ratio. The estimated SOC concentrations from stir-frying, pan-frying, deep-frying, boiling, and steaming were 709.2 + 220.4, 262.1 + 60.6, 119.9 + 18.6 μg/m3, 17.6 μg/m3, 5.0 μg/m3, respectively. The results of cooking-related SOC/OC ratios (81.1% + 2.8%, 85.0% + 1.1%, 79.7% + 4.7%, 40.0%, and 23.0% for stir-, pan-, and deep-frying, boiling, and steaming, respectively) can be used in source apportionment and also be helpful in developing control strategies of particulate carbon pollution.

The building indoor environment is formed under the combined influence of outdoor climate. The existing research mainly simplifies the outdoor environmental parameters into a single parameter for building simulation and human thermal comfort analysis. However, it is difficult to reflect the comprehensive impact of comprehensive environmental information carried by different wind directions on people and buildings. Therefore, this paper aims to explore the characteristics of environmental information in different wind directions and its impact on human perception and indoor environment through empirical research. In this study, it was analyzed using the Universal Thermal Climate Index and two experimental rooms with different shading and ventilation filtering modes. The weighting factor of the comprehensive information of the outdoor environment on people and buildings is calculated by the entropy weight method. This study showed that the urban meteorological station and the building microclimate comprehensive environmental information are quite different, especially the wind speed and direction. It found that the human perception temperature of the architectural microclimate is significantly higher than the urban scale. The results show that the influence factors of the wind direction of the urban scale and the architectural microclimate on human perception are 8% and 4%, respectively, which is almost the same as the influence of temperature and relative humidity. This study indicated that the influence of wind direction on the comprehensive environmental information of people and buildings is not negligible.

This paper investigated the variation characteristics of ambient atmospheric PM2.5 and its influence on indoor environment, with considering several monitored residential buildings in Beijing, China. Conditions were considered for the room by air infiltration, with all the external windows closed and no indoor PM2.5 pollution sources. The constant monitoring of both outdoor and indoor PM2.5 mass concentrations was respectively made for one year from March 2016 to February 2017. Meteorological parameters were monitored simultaneously to be correlated with PM2.5 mass concentrations and indoor-outdoor concentration ratios. The results indicated: (1) Size of more than 90% of atmospheric particles were under 1 μm. (2) The monthly-average concentrations of outdoor and indoor PM2.5 tended to be highest in winter, followed by autumn, spring and summer. Additionally, the average I/O ratios in summer were lower compared to other three seasons. (3) PM2.5 mass concentration was significantly influenced by ambient wind speed and relative humidity. However, outdoor temperature played a negligible role in PM2.5 mass concentrations. (4) Better window airtightness will help to keep a high-demanded indoor environment by resisting atmospherics PM2.5 going indoors.

With aging, human body changes. The elderly normally have problem in thermoregulation and sleep quality. Thus, a cold bedroom environment may cause the sleep problems of the elderly. This study focused on the effects of covering heating and mattress heating on sleep quality of the elderly. Experiment was carried out in the subjects’ own bedrooms in winter. Twelve elderly people were exposed to three conditions, following their daily sleeping schedule. Their sleep quality was evaluated subjectively using questionnaires and objectively with a continuously monitored wristband, called Fitbit Charge 2. Compared with no heating, the subjects felt warmer and had higher SE, longer TST, shorter SOL under two heating conditions. The subjects had shorter WASO and higher SE under covering heating, compared with mattress heating. These results suggest that bed heating improves sleep quality of the elderly in a cold environment, which is affordable and convenient for the elderly in cold winter, especially the covering heating.

Air carrying energy radiant air-conditioning system (ACERS) is a new type of radiant air conditioning system. The ACERS has many installation forms, such as ceiling type, and the composite type of ceiling and sidewall together. The indoor thermal environment of composed ACERS in winter has been investigated by field test in this paper. When the indoor setting temperature is 16 °C and 18 °C, the indoor temperature is about 15.5–19 °C and 17–20 °C, and the floor temperature can be maintained at 13.3–15.2 °C and 13.5–15.8 °C, which can solve the problem of cold feet. Besides, through the analysis of the horizontal and vertical distribution of indoor temperature and humidity, it is found that indoor thermal and humidity environment is uniform. The horizontal temperature difference is less than 1 °C, and the vertical temperature difference is less than 3 °C. These results indicate that the composed ACERS can create a fairly uniform indoor environment and meet the thermal comfort requirement. In addition, by comparing the floor temperature inside and outside the table, the results show that the shelter of desks or chairs in office buildings have great influence on floor temperature, and the radiant sidewall can largely increase the floor temperature. This research verifies the feasibility of winter heating of the composite ACERS, and is helpful for the reasonable heating parameters design and operation of the novel system in the future.

To solve the heat dissipation problem of high power integrated electronic equipment, a micro heat pipe radiator proposed by the composite plane wall algorithm the thermal resistance has been calculated, an equivalent thermal conductivity of plate heat pipe was determined. The distribution temperature at different heating power was obtained. The comparison was shown that the advantage of heat transfer of the novel micro heat pipe was more visible, and the average temperature of the substrate surface was lower 7 °C than that of the traditional micro heat pipe. By simulation, it was shown that the micro heat pipe effectively diffuses concentrated heat flux and had a proper and uniform temperature characteristic at high heat flux. The variation trend of chip temperature and heat resistance of radiator was carried out by analyzing the effects of heating power on heat transfer performance of the radiator respectively and avoiding the thermal stress concentration of the substrate.

What is the difference between the thermal sensation and skin temperature in transitional spaces with or without air-conditioning? Is it necessary to have intensive air-conditioning in transitional spaces of southern China? In order to answer these questions, this paper presents a comparative study performed in a selected shopping mall with two transitional spaces–one with air-conditioning, the other without. The results show that the thermal sensation and skin temperature is different due to the presentation of air-conditioning. It also indicates that air- conditioning for the transitional spaces is needed in southern China. Meanwhile, the study involves continuous measurements of the skin temperature of twenty students while they simultaneously filled out a questionnaire. When subjects passing these two transitional spaces, different skin temperatures and its variation rates result in inconsistent thermal sensation. However, there was a linear relationship between the thermal sensation and the variation rate of mean skin temperature was obtained. These findings can provide valuable information for a good guide to air-conditioning design in transitional spaces.

Partitions are widely installed in commercial buildings, which could block the supplied air and then have an influence on indoor environment. This paper mainly aims to investigate the performances of mixing ventilation (MV), displacement ventilation (DV), and stratum ventilation (SV) in a partitioned office via computational fluid dynamics (CFD). A simulation model was established and validated through experimental measurement. The distributions of temperature and carbon dioxide (CO2) concentration, predicted mean vote index (PMV), and local mean age of air were examined. The results indicated that the partition had significant effects on ventilation performances under DV, wherein the obstacle effect of the partition could lead to both heat and contaminant accumulations around the occupant, and then resulted in a risk of thermal discomfort as well as a reduction of inhaled air quality. In contrary to DV, the indoor air quality and thermal comfort of occupant were slightly influenced by the partition under MV and SV. With the same air change rate and supply air temperature, SV exhibited a better cooling effect and ensured a higher inhaled air quality than MV and DV in a partitioned office. The results of this study could help to provide a reference for the design of the air-conditioning system in a space with partition.

In order to study the thermal environment of office prefab house in summer, the field survey investigation, including thermal parameters and questionnaire survey, was carried out in prefab houses of five building site in Guangzhou. And 749 valid questionnaires were obtained. The results showed that the indoor temperature and relative humidity are both high in most of the time, it had a strong correlation with the outdoor environment changes and the value difference is little. In addition, the upper limit of the measured acceptable temperature is 29.27 °C, the comfort temperature zone is 24.99–28.17 °C, the neutral temperature is 26.44 °C, and the preferred temperature is 25.8. Only 64% of the samples are in the range of comfort temperature, which indicates that the indoor thermal environment needs to be improved. There is obvious difference between the Predicted Mean Vote (PMV) and Mean Thermal Sensation Vote (MTSV). Therefore, the PMV model is needed to modify to improve correction for evaluation of the special thermal environment in prefab house.

This study intends to investigate indoor thermal environment and the thermal comfort status of the elderly people living in urban apartments and rural wooden houses in Hunan, China during the winter. Field measurements and questionnaire surveys were conducted among 164 healthy elder people over 65 years old in 99 residences. Results show that average indoor temperature in both areas are below 15 °C and the temperature difference between different rooms is very large in rural wooden houses. The elderly living in urban apartments are more satisfied with the overall indoor thermal environment and have more diversified measures for thermal adaptation than those living in rural wooden houses. The predicted neutral temperatures for the elderly are calculated to be 14.6 °C and 15.5 °C in rural and urban area respectively, which are higher compared with the young. The results of this study can provide a reliable reference for managing the thermal environment of the residents for the elders.

A comfortable indoor thermal environment is usually controlled through air conditioning, which can greatly improve work efficiency. However, current air conditioning system design may not consider the spatio-temporal distribution of the indoor environment for large-scale buildings, so the air conditioning system needs to be optimized. Few studies have examined such optimization related to different weather conditions outside the building. This study presents a method to formulate an air condition adjustment strategy for each specific zone in a library with large glass curtain walls, based on the diurnal change of thermal environment. We measured the indoor thermal environmental conditions and recorded the thermal comfort perception of room occupants. The Predicted Mean Vote (PMV) and apparent temperature model were adopted to predict the occupants’ thermal comfort, resulting in a suggested comfort range. Based on our results, the comfortable range of PMV and apparent temperature was identified, and this comfortable range could be used as a basis for an example of adjusting the air conditioning system to improve indoor thermal comfort.

Field measurement is a major method for studying issues related to the outdoor thermal environment. Through accurate acquisition and objective analysis of the measured data, the rule of dynamic physical parameters can be obtained. This paper analyzes the outdoor thermal environment researches carried out in China and overseas in recent years and puts the emphasis on field measurement at fixed points. Conclusions include a summary of three types of arrangement methods of measuring points based on multi-variable control method, pre-analysis method and lumped parameter method. Besides, two types of ways to improve the reliability of measurement results are also given. Finally, relevant suggestions for the future standardization for measuring methods of outdoor thermal environment are put forward.

Ultrafine particles (UFPs) are produced by human activities in outdoor and indoor environments. It is important to control indoor UFPs for their health effects on human and long duration that people spend indoors. Filtration is important in mechanical ventilation system for UFP removal to reduce human exposure to UFPs. The filtration efficiency for particle removal depends on particle diameter. Thus, we selected nine respective filters and their combinations to measure size-dependent efficiencies for UFP removal and the pressure drops. The 4th-order polynomial equations were developed from fitting results. The total efficiencies for UFP removal were estimated based on the polynomial equations and the measured size distributions of ambient UFPs. The total efficiencies for UFP removal and pressure drops of combinations of fine filters are comparable to those of a single HEPA filter. The application of combinations of fine filters needs further study in the future. The filtration efficiencies of these filters are relatively low, which may be caused by the lack of good tightness and need to be improved in the future.

We mapped thermal sensitivities of 318 skin spots over 15 body parts, in 48 college students. The results show that body parts had wide variance in thermal sensitivity. The foot, lower leg and upper chest are much less sensitive than average, while the cheek, neck back, and seat area are very sensitive to both cooling and warming stimuli. To examine any sex differences in thermal sensitivity, body-surface-area-matched males and females were selected. Given comparable body size, no significant thermal sensitivity differences were observed between male and female, except for warming of the forearm and chest. These high-density thermal sensitivity data provide the most comprehensive account of the distribution of cold and warm sensitivity across the human body. They can help to guide future developments in energy-efficient personal comfort systems and wearables.

This paper aims to investigate the age-related individual differences of thermal comfort in a science museum, which located in South China, a city with hot–humid climate in summer. Environmental parameters were measured in the field study as well as questionnaires and interviews. The results showed that the occupants’ metabolic rate in the surveyed science museum was higher than that in normal buildings and the adults (above 20 years old) chose lighter activities than the youth (20 years old and younger). The tendency of values growing with the age growth existed in both the highest upper limit of comfortable temperature and acceptable temperature. The adults had a higher values in the neutral temperature (25.45 °C), a higher upper limit of comfortable temperature (28.61 °C), and acceptable temperature (32.7 °C) than the youth, while the youth had a narrower comfortable temperature range (22.83–27.24 °C). Furthermore, the elder adults also showed a stronger adaptability and resistance to the warm environment. This study provides references for environmental design and energy conservation of science museums.

The part results of a CCHH (a retrospective cross-sectional survey conducted in Shanghai) can be used to study the prevalence of obesity in children aged 4–6 of Shanghai and the effect of early family care. The survey results showed that the overall overweight and obesity rates of children aged 4–6 years of Shanghai were 18.3% and 15.6%, respectively. The overweight and obesity rates in boys aged 4–6 years were significantly higher than those in girls aged 4–6 years (P < 0.05). The results of a logistic regression revealed that in early care, father’s smoking may have relevance with overweight and obesity of children during pregnancy and after birth and those children who enter preschool later are more likely to be overweight. Our research shows that the preschool children in Shanghai have a higher prevalence of overweight and obesity. Father’s smoking and children entering preschool later may have a relevance with overweight and obesity in children aged 4–6 years of Shanghai.

A sphere-shaped experimental setup is assembled by organic glass via mass polymerization in a layer-by-layer manner from top (north pole) to bottom (south pole) in a cylindrical experimental hall. For each layer, the thermal bonding joints of both inner and outer surfaces need to be annealed by a heating belt with heat flux density of approximately 4200 W/m2. Due to the requirements of the experiment, the temperature should be controlled within the range of 21 ± 1 °C to avoid physical deformation. In this paper, rapid release and diffuse process of high heat (0–300 s) is simulated using transient CFD method and the applicability of two ventilation schemes, e.g., general ventilation and push–pull ventilation, is investigated. The temperature distributions of all the areas above the layer under polymerization and heat exhaust efficiency are used to evaluate the effects of different ventilation schemes on heat dilution. The results show that, first, the high heat release and diffusion results in rapid buoyancy and general ventilation alone cannot maintain temperature increment. Second, the push–pull ventilation can effectively minimize the buoyancy caused by the heating sources and maintain thermal environment and increase the heat exhaust efficiency.

As one of the complex underlying surfaces, the water body improved the local thermal climate in the surrounding area especially on water vapor diffusion and temperature. Therefore, in this paper, taking the water effect and factor analysis as the research object, based on the CFD method, key factors were analyzed which influence thermal and humidity environment in the waterfront areas. The factors mainly discussed in this paper are building type, building floor area ratio, embankment height, distance from water body, and landscaping. Each factor includes five levels. The results showed that the building floor area ratio and embankment height were the most significant factors for the vapor diffusion, followed by landscaping and the building type had the minimum influence. For the temperature, all factors had no obvious gap. Besides, the building floor area ratio was strongly linear correlated to water vapor diffusion but poorly to temperature.

Exposure to particulate matter could cause a wide range of adverse health effects on human beings, which has widely drawn attention. Filtration applications can effectively remove particles and reduce the risk of diseases for humans. Electret media have been often used in residences and commercial buildings due to the permanently charged fibers that contribute to the higher efficiency and lower pressure. However, the efficiency of electret filters would decrease with the increasing loaded dust. To investigate the loading performances of electret media, long-term loading tests were conducted to obtain the time-dependent efficiencies of medium- and high-efficiency electret media that were challenged with polydisperse potassium chloride (KCl) and diethylhexyl sebacate (DEHS) particles, respectively. Results showed that there was no reduction in efficiency of high-efficiency electret media while loaded by KCl. In contrast, the efficiency of high-efficiency electret media increased continually with the increasing loaded KCl mass. However, the efficiency of medium electret media firstly declined and then increased with the accumulation of KCl particles on fibers. The different loading characteristics between medium- and high-efficiency electret media were related to the mechanical structures and charges in fibers. Moreover, efficiencies of medium- and high-efficiency electret media both decreased as a function of deposited particles when electret media were exposed to DEHS. The decline of efficiency was attributed to the factor that the thin liquid film around faces of fibers formed by deposited DEHS particles degraded the electric filed, which was different with the dendrite structures formed by KCl particles.

This paper aims to present the measurements and analysis results of welding fume concentration and particles character in nuclear island containment. The concentration of fume exposure is measured by using CCZG-2A portable personal fume meter and CEL-712 fume detector. In addition, the morphology, element composition, and particle size distribution of fume particles are analyzed through high-resolution transmission electron microscope (TEM) and energy-dispersive spectroscopy (EDS). The results show that (1) there are mainly three types of fume particles in the confined space of nuclear island, namely spherical metal particles with particle size of 0.3–2 μm, non-metal particles with particle size of 1 μm, and welding primary and secondary fume particles with particle size of several nanometer to microns. (2) On the one hand, welding workers’ individual fume exposure exceeds the standard rate by 75%, and the highest concentration exceeds the standard by more than 6 times. On the other hand, the possible welding exposure of non-welders is also beyond the standard rate, which exceeds the prescribed limit rate between 3 and 16 times. (3) Welding fume particles in confined space of nuclear island are located in the accumulation mode with particle size of 0.08–2.0 μm. The median diameter of the particle number is 0.3 μm, in which the particles account for 67% of the total particle number in the range of 0.15–0.6 μm, and 95% of the total particles in the range of 0.07–1.24 μm. The results of this study will provide support for computational fluid dynamics (CFD) numerical simulation of nuclear island welding fume decontamination in the next step.

Most of the emission sources of volatile organic compounds (VOCs) are introduced indoors during the construction stage. In order to investigate the chemical compositions and the concentration variation patterns of indoor VOCs, field measurements were carried out periodically in a newly built apartment in Nanjing. Typical VOCs identified during the construction stages were benzene, toluene, acetic acid-butyl ester, ethylbenzene, styrene, and undecane. The measured concentrations of formaldehyde and VOCs in rooms were slightly different. However, the overall concentration variation patterns of VOCs in different rooms were similar. The concentrations of formaldehyde and TVOCs ranged from 20.1–82.2 μg/m3 to 163.3–2910.5 μg/m3, respectively. Formaldehyde concentration increased significantly after putty, floor, and doors were introduced. VOCs concentrations increased and reached the peak value after the wooden doors were installed. The indoor air quality during the construction stages was poor even though the window was kept opened all the time.

Impacts of human activities on the indoor air quality of hospitals almost focus on operating theaters and isolation rooms. Few studies pay attention to the normal outpatient department such as waiting areas, where crowds always gather. By utilizing unsteady CFD simulation with SST k − ɛ model and dynamic mesh, this paper investigates how the human activities of the health-care worker (HCW) and patients influence the airflow and pollutant distribution in the waiting area of an outpatient department in a general hospital in Wuhan. The results indicate that wake flow caused by legs moving forward is obviously weaker than that of arms and body with the model of swinging arms and legs when compared to the simplified model of human walking. The swinging arms and legs can accelerate the wake flow velocity, even larger than the human moving speed. The attenuation of wake flow velocity is also rapid. The increase in the human moving speed can speed up the spread of the pollutants, but cannot change the pollutant concentration.

Due to the enclosure and low efficiency of ventilation systems inside the tunnels, pollution levels are high, which have become a hot spot research issue recently. The aim of this study is to analyze the characteristics of unsteady particle dispersion when a fleet of vehicles pass through the tunnels under different vehicle speeds (20–60 km/h), combining a realizable k − ε model, Eulerian passive scalar model, and dynamic mesh model. A 450-m three-dimensional road tunnel model containing a fleet of vehicles inside and another 450-m-long outdoor environment model connecting the tunnel exit were both established. CO was selected as a pollutant exhausted from vehicles. The results indicated that pollution levels were severe inside the tunnel, at least 2 times higher than the limitation, and even the traffic wind was significantly high at 60 km/h. An optimal design for ventilation systems should be required to decrease the pollution levels around the tunnel outlet.

The composition of decoration pollution is complicated and this paper takes formaldehyde as an example for research. In interior decoration, people often choose aesthetic program at the cost of pollution emission. The composition of decoration pollution is complex. This study takes formaldehyde as an example to study. Based on the finite difference method, this paper simulated the emission of formaldehyde by using CFD software. It mainly discussed the distribution of newly decorated buildings formaldehyde emission and the impact factors such as indoor compartment separation, windows opening form, cabinet furniture interior layout and wind speed in the typical houses. Under the condition of natural ventilation, the simulation results show that the formaldehyde concentration in the room with downwind direction is higher than that of upwind, and it inverses proportion to the wind speed. Therefore, increase the sweeping space of the through air and promote the emission of formaldehyde indoors that selecting doors and windows with large open area, reducing the partition of the indoor partition walls, and putting the furniture within local downwind direction.

Aiming at the safety operation problem of the machineroomless elevator installed in existing residential buildings due to the overheating of the elevator shaft in summer, the author tested and analyzed the elevator operation of an existing residence in Chongqing, and used DeST software to simulate the temperature in the shaft. The purpose of this paper is to find out the temperature change in the shaft of the machineroomless elevator installed in the existing residential buildings under the high temperature environment in summer and obtain the minimum ventilation rate to ensure the hot environment in the shaft according to the thermal performance of different types of well enclosure structure, so as to provide the basis for the shaft ventilation design of the elevator project installed in the existing residential buildings. The conclusion of this study can provide reference for the design of elevator renovation project of existing residential buildings in similar climate areas.

Due to modern lifestyles, commercial streets have become an indispensable place in urban life. Pedestrian wind environment is one of the primary concerns in commercial street design since it has direct influences on urban heat island effect, indoor and outdoor thermal comfort, outdoor air pollution and indoor air quality. To investigate pedestrian wind environment of a commercial street, a case study was performed on Beijing Wangfujing Commercial District in China and Tokyo Sensoji Temple District in Japan separately. First, the original models of these two commercial streets were established based on real streetscapes and the surrounding buildings. The velocity filed under typical summer climatic conditions was then output to assess the wind environment of each street. The results show that pedestrian wind environment under the current design is not comfortable for Beijing street and Tokyo street. To improve this situation, further work was conducted on optimization of current street design, specifically on the determination of a suitable aspect ratio H/W (W is the width of the street and H is the height of the street buildings). In this step, simplified models derived from original models of each street were used for simulation. According to present simulation results, the determined aspect ratio H/W is about 0.80 and 0.30 for Beijing street and Tokyo street, respectively. It should be noticed that this ratio could differ on the height of the street buildings as well as on the climatic condition of the street locations.

The kitchen is an indispensable functional space in people’s lives; meanwhile, it is the main area of indoor pollution in China. Therefore, in order to improve the indoor air quality of kitchens, more and more researchers are conducting in-depth researches in air pollution in the catering kitchen aerosol diffusion. Based on the actual situation of the typical Chinese restaurant (pot) of the Commercial Complex in Xi’an, this paper established numerical simulations under different spacing conditions for two unequal heat sources. The thermal plume state above the heat source and the aerosol diffusion mechanism were studied using FLUENT numerical simulation software, and the control of aerosol diffusion was discussed. The results show that when there are two heat sources and the heat source strength conditions are given, the spacing of the heat sources will have a significant impact on the plume state and diffusion above the heat source. The smaller the spacing of heat source, the stronger the coupling and interference generated by the heat plumes formed from two heat sources.

A scaled model chamber was used to study the thermal environment and stratified air-conditioning load characteristics of a large-space building under periodic thermal disturbance. Seven experimental cases were conducted with different thermal disturbances and stratification heights. The results showed that the vertical temperature distributions were similar. At the same stratification height, when the average value of the periodic thermal disturbance increased by 50%, the average value of the stratified air-conditioning load increased by approximately 60%. In addition, under the same periodic thermal disturbance, when the stratification height decreased by 0.6 m, the stratified air-conditioning load decreased by 15.5%.

Local heating or cooling of body has been the research hotspot in the field of thermal comfort. This paper analyses the impact of local cooling of forehead, back, and foot on overall thermal response under specific environmental parameters. The experiment uses thermal manikin as the subject. Based on the orthogonal experimental design, in a climate chamber with different ambient temperature of 28, 31, 34 °C, local cold stimulation of 22, 24, 26 °C were given to the different three parts of thermal manikin. According to the average skin temperature recorded, thermal comfort could be evaluated. The results indicated that local cooling of each one of the three parts can reduce the average skin temperature to some extent. The key part of local stimulation is foot > back > forehead. The findings have important implications for further research.

To determine the thermal comfort of people from different climate zones in the naturally ventilated building in summer, subjects were divided into two groups, namely: (a) HSCW group—subjects who grew up in the hot summer and cold winter zone, and (b) CZ group—subjects who had lived in the cold zone. Field studies were performed from May to July 2018. The results indicate that the neutral operative temperature were 24.6 and 24.0 °C in HSCW group and CZ group, respectively. The upper limit of 80% acceptable operative temperature of the latter was 2.5 °C higher than the former. There were no significant differences between local skin temperatures and mean skin temperatures except for the hand back and thigh in two groups. The adaptive coefficient (λ) were 0.52 (CZ) and 1.0 (HSCW). The subject’s heat-resistance capacity and thermal adaptability in HSCW were better than CZ group.

Outdoor particulate is an important source of indoor particulates, which can cause serious harm to human health. Industrial and transport emissions and particulate matter aerosols emitted by the combustion process are the main sources of pollution in the urban air environment, resulting in continued growth in outdoor particulate matter concentrations. Study the correlation between indoor and outdoor particulate matter concentration by measuring the concentration of particulate matter indoors and outdoors in different functional residential rooms in different seasons. The I/O value of indoor and outdoor particulate matter was established, and the influence of outdoor particulate matter concentration on indoor particulate matter concentration was analyzed by experimental data. The I/O values of different functional rooms are also different, and the I/O value of the bedroom is smaller than the I/O value of the living room and kitchen. The research results will lay the foundation for further research on the control method of indoor particulate matter pollution in urban residential buildings.

Based on an engineering training centre, a scaled model laboratory with a geometric ratio of 1:4 was established. The indoor thermal environment and stratified air-conditioning load (SACL) of the scaled model laboratory with low-sidewall air supply was experimentally studied. The heat gain through the building envelope was simulated in the form of step thermal disturbance by the electric heating film attached to the walls and roof. The lab was commissioned by a series of pre-experiments, and seven experimental cases were conducted with different exhaust ratios and indoor heat source heights. The experimental results indicated that when the exhaust ratio was increased from 0 to 21.63%, the internal wall surface temperature was reduced by 2.85 °C, the indoor air temperature in the air-conditioned area was reduced by 0.84 °C and the SACL was reduced by 18.90%.

Ultra-low energy building (UB) is being into real construction in China as the symbol of the higher energy-performance building standards. It is a great challenge to choose the appropriate terminal form of air conditioning that can achieve the indoor environment with low energy consumption and high comfort for UB in hot summer and cold winter areas of China. And the radiant cooling (RC) system could be considered because of the advantage of thermal comfortability and energy saving. The thermal response of the room with RC system has a great influence on thermal sensation of the occupant. This paper focuses on thermal response characteristic of UB and common energy-efficient building (CB) with RC system. A simplified steady-state heat transfer mathematical model for a typical office is presented in this study. According to the results, there is slight temperature fluctuation for wall surface and indoor air of UB but drastic for CB. Also, the thermal response characteristic of room with RC system for two buildings shows that indoor environment of UB is more sensitivity to RC system than that of CB. The research indicates that the UB presents more uniform and stable indoor thermal environment compared with CB with RC system, and this provides proposal for the optimal air conditioning of UB.

Although good ventilation is an important method for diluting and removing indoor aerosol pollutants in the hospital wards, it caused huge energy consumption at the same time. Therefore, it is important to understand air and pollutants transport between the multiple-bed and to improve the ventilation system design for the hospital wards. This paper developed a new type of air supply diffuser design by adding a quarter sphere air diffuser at one end of the semicircular air supply diffuser and a vertical return air outlet besides the opposite side of the wall at the bottom of the return air type for reducing the cross-infection rate, the air supply volume and the energy consumption at much lower cost simultaneously. Computational fluid dynamic (CFD) was employed to establish a three-dimensional ward model which arranged the beds around the ward and simulate the ventilation process of diluting and removing pollutants from the ward space by using the standard κ-ε model and component transport model. Numerical simulation shows that vector flow with vertical return air outlet can effectively reduce the discharge time of the airborne pollutants; the vector flow air supply with the hemispherical air supply diffuser can achieve the same effect on removing pollutants as the vector flow air supply is on the basis of less air supply volume. The results of the present work will provide more choice for ventilation modes in the hospital wards, which is of great significance for energy conservation and emission reduction.

The aging degree of China’s population is deepening. According to the prediction, by 2020, the number of China’s aging population will reach 205.5 million, and by 2030 the aging degree of China’s population will reach the peak, and China will enter the most serious stage of aging society. This paper investigates the indoor environment of 10 households over 65 years old in Guangzhou, China in summer. Temperature and relative humidity were measured in the living room and bedroom of each house. At the same time, we learned about the physical conditions and living habits of 100 elderly people through questionnaires. The results of this study help to better understand the living environment of elderly people in Guangzhou in summer.

The thermal adaptation process of migrants is a complex system considering psychological, physiological and behavioral layers, also accompany space-time and development to change. This study explored constraints affecting adaptation process, especially in behavioral level. A long-term tracking field study has been conducted in Xi’an, including Indoor thermal environment parameters, subjective questionnaires, and behavioral adjustment methods. The migrant groups from severe cold area, hot-summer and cold-winter area and hot-summer and warm-winter area were recruited. The results showed the behavior adjustment modes of migrants were significantly influenced by the thermal experience of native residence. Migrants with better thermal experience showed the diversity of behavior adjustment. In addition, behavioral acclimation was relatively a slow process compared with thermal perception. The results could provide reference for studying dynamic process of migrants’ thermal adaptation and contribute toward indoor climate design for migrants.

The fiber filter has a good filtering effect on the particles, and how to improve its performance has become a research hotspot. This paper aims to use the DPM model in Fluent to numerically simulate the process of filtering particulates in fiber filters, and to find ways to improve its filtration performance. The fiber diameter was kept constant at 16 µm during the simulation, and the filtration velocity, particle size, fiber structure, and fiber filling rate were changed. The results show: The staggered structure fiber filter has better filtration performance than the parallel structure; The filtration resistance agrees well with the Davies experimental correlation, increases linearly with the increase of filtration velocity, and increases nonlinearly with the increase of fiber filling rate; The higher the fiber filling rate, the higher the filtration efficiency; the higher the filtration velocity, the better the filtration performance.

This study collected samples from 93 residential buildings in Shanghai. Based on the change of CO2 concentrations measured in these samples, we have analysed the relationship between bedroom air infiltration ratio and the residential characteristics during night, when doors and windows were closed, from 00:00 a.m. to 6:00 a.m.. The result shows that the average CO2 concentration in the bedrooms was 1448 ppm at night. CO2 concentrations from 89.2% of the tested bedrooms were higher than the upper CO2 level required by GB/T18883-2002 (over 1000 ppm). Analysis of variance shows significant factors affecting the bedroom air infiltration ratio at night including the type of window, season, gap-length of doors and windows, and type of residence. These four factors rank according to Spearman correlation analysis as follows: window type, detection season, door and window gap length, residential type. This paper is significant for its guidance on keeping the balance between building energy consumption and indoor air quality.

This study aims to investigate thermal comfort of residents with a kind of personal heating device (Huoxiang) in winter. A field survey was carried out in towns with the cold-humid climate in the west of Hunan Province, south China. The investigated buildings were natural-ventilated in winter, and the indoor environment much deviated from the comfort zone suggested by ASHRAE Standard 55. Huoxiang is a kind of electric heating device which is widely used by the local residents for keeping warm in winter due to the lack of central heating systems and air conditioning systems. This survey included physical measurements, questionnaires, and interviews. The results showed that residents who were using Huoxiang could still have a neutral thermal sensation and a high level of comfort (99.1% thermal acceptability rate) when the indoor ambient air temperature was 8–14 °C. Meanwhile, the relative humidity was relatively high, but because of the low air temperature, the humidity ratio in air isn’t actually high. And more people would feel ‘dry’ when they were using Huoxiang, through analysis, this feeling of ‘dry’ would affect thermal comfort to some degree. Moreover, Huoxiang has a simple structure, the ability to keep users comfortable make it possible to be applied in small towns and rural regions with a low economic level.

Occupants’ behaviors over air-conditioning systems influence building energy consumption to a great extent. It is important to explore occupant use behaviors in buildings. However, when having access to controlling air-conditioning thermostat, and a ceiling fan speed, it is unclear how subjects would control the two cooling strategies. The objective of this experimental study is to explore how occupants use air-conditioners and fans, and develop predictive models for occupants’ control behaviors. 20 subjects participated in the experiments. The initial indoor temperatures were set at 26, 28 and 30 °C. And two modes were set up, i.e. subjects using a ceiling fan or not. The results showed that in a user-controlled environment, indoor temperatures, thermal comfort and occupant’s control behaviors over a thermostat of air-conditioning system had exponential relationships over time. Besides, with or without fans, non-linear correlations between skin temperatures and occupant’s requirements for lowering indoor temperatures were found.

This study aims to optimize the parameters of a set of partition-type radiant heating terminals to provide better thermal comfort for people in cool environments. The UCB Comfort Model was used to validate experimental results and optimize parameters of partition-type radiant heating terminals. The results indicated that the revised model established using the UCB Comfort Model was reliable when predicting overall thermal sensation of subjects with a deviation value of ± 0.3 in cool environments. On the basis of the simulation model, it was found that the surface temperature and position of the terminals played an important role in maintaining comfort of users in cool environments. The surface temperatures should be at least 55.5 and 33.5 °C with air temperatures at 14 and 16 °C. When surface temperatures were 50 °C and 60 °C, the minimum distances of radiant terminals at 14 °C should be 0.30 m and 0.61 m respectively, but at 16 °C, the distances can be increased to 1.29 m and 1.33 m.

The air-conditioning-use (AC-use) behaviors of building occupants have a significant impact on indoor thermal environments and energy consumption of air conditioners. In an office building in Changsha, some parameters including indoor and outdoor air temperatures, relative humidity, the on/off states of air conditioners, and others were recorded from May 1 to October 31. Indoor environmental parameters were analyzed and indoor thermal comfort was evaluated during summer. In addition, the logistic regression was used to develop a statistical model to predict the AC-use behaviors of office building occupants, compared with self-paid residential buildings. The results indicate that indoor thermal environments were not affected by outdoor environment with personnel air conditioning, and the indoor thermal environments were in the comfort zone in 70.3% of cooling period; According to the proposed formula in the logistic regression, the outdoor tolerant temperature was found as 30.7 °C; The indoor tolerant temperature was found as 28.3 °C; In summer, the probability of turning on air conditioners in office buildings was longer than residential buildings generally. This paper also provides references for energy saving in air conditioning systems in office building in the future.

Air pollution is a worldwide problem, especially for China which is one of the countries with the worst PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) pollution in the world. A wealth of studies proved that PM2.5 pollution can lead to diseases such as cerebrovascular, respiratory and cardiopulmonary diseases. Considering the randomness of the behavior pattern of the crowd, PM2.5 population exposure distribution, population attributable fraction (PAF), and burden of disease were estimated on a 10 km × 10 km grid using a model based on two-dimensional Monte Carlo. The results showed that PM2.5 personal exposure in south-eastern Beijing is relatively large. The PM2.5 population exposure in adults >25 years of age and children <4 years of old was 41.52 μg/m3 and 37.48 μg/m3 in 2016. A total of 4538 (95% uncertainty interval (UI): 2595–6722) premature deaths were attributable to PM2.5 exposure, 2468 (95% UI: 2595–6722) of them from ischemic heart disease (IHD) which was responsible for the most.

China is experiencing severe PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) pollution. Controlling indoor PM2.5 concentration is critical to reduce personal exposure to PM2.5 as people spend most of their time indoors. A two-dimensional Monte Carlo model was applied to estimate the PM2.5 population exposure distribution, potential impact fraction (PIF) and decrease of premature mortality by reducing indoor PM2.5 to World Health Organization (WHO) Air Quality Guideline of 10 μg/m3, WHO Interim Target levels 1, 2, and 3 of 35 μg/m3, 25 μg/m3, and 15 μg/m3 with indoor cleaning. 1376 (95% uncertainty interval (UI): 943–2438) premature deaths would be averted from controlling indoor PM2.5 to WHO Air Quality Guideline, which accounts for 0.0114% of the total population in Beijing, greater than that from controlling to WHO Interim Target 3 level (536, 95% UI: 381–952). The results showed that indoor PM2.5 control by indoor air purifier is an effective and easy method to protect human health from PM2.5 pollution.

With the increase of urban population, it is vital to create thermally comfortable outdoor open spaces. To obtain data for examining the relationship between the meteorological parameters and outdoor thermal sensation, this study conducted thermal comfort tests on 30 subjects on the campus of Tianjin University. Our results indicated that in autumn and winter, outdoor solar radiation had the greatest influence on thermal sensation, followed by air temperature, wind speed, and relative humidity. Under different combination of meteorological conditions, radiation, temperature and wind speed had different effects on thermal sensation: (1) When the radiation value was low (mean radiant flux <450 W/m2), the air temperature change from 14 to 22 °C did not affect the thermal sensation. (2) When the radiation value was high, in the high-temperature range (28–30 °C), the increase of the radiation value significantly increased the thermal sensation; (3) The cooling effect of wind speed on thermal sensation was large under high and low solar radiation. The acquired data in this study could help the design and construction of thermally comfortable urban open spaces.

The effects of indoor thermal environment on learning efficiency and physical health of teachers and students are significant in the university library. This investigation studies thermal environment and comfort in a university library in Guangzhou through conducting the microclimate measurement and questionnaire survey. The results show that there are obvious differences in the thermal environment between the library reading room and the library atrium reading space. In library reading room the operative temperature ranged between 24.5 and 27.5 °C, lower than that in library atrium ranging from 27.5 to 31 °C. In addition, it is found that the neutral temperature of reading room is not obviously different from the preferred temperature, and the neutral temperature of atrium reading space is higher than the preferred temperature. The Predicted Mean Vote (PMV) correction models of libraries are obtained by linear regression, which can be used to evaluate the thermal comfort of the library for the students.

Field measurements were conducted on temperature distributions for a long-distance transport bus station under natural ventilation during transition season in city Nanjing at the southern China. Four climate regions are divided for the southern china based on the outdoor meteorological data and one typical city is selected out for each climate region. EnergyPlus software is adopted to simulate the station’s temperatures under natural ventilation for each city. Results are compared some good with that of the measured. The available times of natural ventilation are respectively determined based on an improved thermal adaptation model. The findings are that for the climate region II and III, the building achieves the medium natural ventilation cooling potential; for the region IV, the building achieve the lowest potential; whereas for the region I, it has the best potential. This study contributes to extend the using of natural ventilation for public buildings in southern China so as to realize the HVAC energy saving.

In this investigation, the measurement thermal parameters and thermal comfort field survey were carried in six air-conditioned hospitals in Guangzhou. A total of 114 valid questionnaires were collected. Based on the data, there were strong linear regression relationships between PMV and MTSV and operative temperature. The neutral temperature was 24.39 °C from the linear regression of MTSV. The thermal comfort temperature which meets a satisfaction degree of 90% or 80% ranges from 22.83 to 25.94 °C, 21.74 to 27.03. In addition, the neutral operation temperature was 23.75 °C from the PMV model. The thermal comfort temperature which meets a satisfaction degree of 90% or 80% ranges from 22.00 to 25.50 °C, 20.77 to 26.73. Comparing the MTSV and PMV, the MTSV was lower than that of PMV. The preference Top was obtained by Probit regression analysis curve intersection point was 24.43 °C. By Actual Percentage Dissatisfaction obtains 90% or 80% of the medical staff acceptable comfort temperature upper limit of 24.71 °C, 25.53 °C.

To deal with the worsening sanitation of public toilets, Chinese government put forward the plan of “Revolution of Toilets” in 2015, which has achieved some research results about improved sanitary condition of independence public toilets and dependence public toilets. However, the sanitary condition of Mobile Public Toilets (MPT), which are used outdoor remains unchanged due to the limits of water supply and the lack of ventilation facilities. In order to find out the influence factors of the internal sanitary of the MPT, in this paper, three groups of normally used MPT in Zhengzhou have been selected as the research objects and thermal environment parameters were measured in summer. In addition, subjectively scoring method has been used synchronously for odor intensity evaluation by six grades. The measured thermal environments and scored odor intensity inside the three objects MPT demonstrated that the indoor environment of MPT is highly unacceptable even for short-term use in summer, appropriate measures should be taken to improve the thermal environments and remove malodor in MPT.

Thermal radiation is an important component of outdoor thermal environment since it accounts for a significant part of thermal load on human body. This study investigated the radiation fields in two outdoor spaces with different Sky View Factors (SVFs) in summer and autumn, and under sunny and overcast weather conditions. The result shows that the decrease of SVF significantly reduced the short-wave radiation due to the block of the sun. In contrast, the change in SVF had a much smaller impact on the level of long-wave radiation. The total level of radiation among seasons had a huge difference, as the difference in the Tmrt among seasons exceeded 30 °C. Weather condition had a smaller impact on the total level of radiation than season, as the Tmrt on a sunny day was only about 10 °C higher than that on an overcast day. The findings of this study provide a database for studying the radiation field and thermal comfort in outdoor spaces.

To determine the classification of electret filters, EN 779 and ISO 16890 have taken the IPA immersion and fumigation as the discharging method, respectively. This study compared the efficiency of electret filtration media discharged by the method of EN 779 and ISO 16890, respectively. It was found that the discharged efficiency of electret media using the method specified in ISO 16890 was lower than those discharged by the discharging method of EN 779. By comparing the discharged efficiency of electret media with the efficiency of uncharged samples, results showed that the discharged efficiency of electret media treated by IPA fumigation was close to the uncharged efficiency. Moreover, the loading experiment that the electret medium was challenged by the liquid DEHS aerosol was conducted to evaluate the long-term loading performance of electret media. It was found that the efficiency of electret sample gradually declined from 92 to 30%.

The newly decorated kitchen is prone to the problem of excessive formaldehyde. For the severe cold regions, inadequate or unreasonable air supplement will affect the removal of pollutants or cause extremely uncomfortable temperature fields. This paper takes the ventilation of the kitchen ceiling as the research object and establishes the physical model of the typical residential kitchen. The CFD simulation software is used to simulate the pressure field, temperature field, and pollutant concentration field of the living building kitchen under the three types of ceiling air inlets, and the kitchen environment under the conditions of no ventilation (door and window penetration) and natural ventilation is analyzed. The ceiling ventilation method using natural pressure difference has better control effect on kitchen pollutants. The simulation results show that the kitchen static pressure fluctuates around −30 Pa under the condition of supplemental air, which prevents the kitchen smoke and smell from entering other rooms. Among them, the opening 3 has the best air distribution effect, the pollutant concentration is stable at 0.051 mg/m3, the temperature is stable at 278 K, and the stove flame will not have obvious swing. It provides a theoretical basis for improving the reasonable airflow organization of residential kitchens in cold region and creating the thermal comfortable environment suitable for kitchen staff.

Concerns about indoor air quality (IAQ) have been greatly increased since particulate matter (PM) pollution poses a serious health threat to humans. Particulate air filter is one of the most economical and efficient solutions to PM purification in commercial or residential buildings. In this study, a micro-nanomulti-layer composite electret filter, composed of polystyrene/polyacrylonitrile/polystyrene (PS/PAN/PS) was controllably fabricated via electrospinning. The outer polystyrene (PS) membrane with diameter of 3.93 µm has large pore sizes, which makes the airflow easy to pass. Additionally, the PS media could store a large amount of space charges because of its large basis weight and high insulation resistance. The polyacrylonitrile (PAN) nanofibers laminated between the two PS membranes could enhance the filtration efficiency for fine particles due to its nanoscale diameter. Combined with the advantages of nanoscale fibers and electret materials, the composite filter exhibited a high filtration efficiency (>99.5%) and a low-pressure drop (37 Pa) to sodium chloride (NaCl) aerosol particles (≥0.3 µm) under an airflow velocity of 5.3 cm s−1. The dynamic energy calculation shows that it could save up to 46.38% in energy consumption compared with the traditional commercial ones. The filter is suitable for high-efficiency particulate (HEPA) air filtration in heating ventilation air conditioning (HVAC) systems or stand-alone portable fan-filter air cleaning systems.

Human health in the extreme weather conditions is a key issue in adaptations to climate change. In the field of world public health, controversies exist in the benefits of long-term use of air-conditioning on human health. This study collected the heat-stroke records of students in summer military training in hot and humid areas of China together with the potential influencing factors through questionnaire, and investigated the impact of history of using air-conditioning on the incidence of heat-stroke. A cross-sectional survey was conducted in 8 schools that conducted summer military training from September to October in 2018, and a total of 6342 valid samples were obtained. Chi-square test and unconditional logistic regression analysis were used to analyze data. Factors of history of using air-conditioning, history of using fan, gender, heat-stroke medical history, health status, and clothing insulation were found to significantly affect the incidence of heat-stroke in military training. The more than 3 years’ history of using air-conditioning was identified as a risk factor and the more than 5 years’ history of using fan as a protective factor for heat-stroke in summer military training. The study helps to figure out the directions of building design and control favorable to human health.

The conditions for opening windows in winter in Liaoning area are limited, and ventilation is an effective mean to solve the problem of excessive formaldehyde concentration in indoors. In order to analyze the status of formaldehyde pollution in the winter of mechanical fresh air system residential buildings, 8 households with fresh air system in Liaoning area were selected to obtain indoor formaldehyde concentration changes by using formaldehyde indoor detection on typical meteorological days and long-term dynamic online monitoring in winter. According to the analysis of the indoor measured data under the closed condition and the mechanical ventilation condition and long-term online monitoring data of the 8 households with mechanical fresh air system, it is found that the indoor formaldehyde concentration can be reduced to some extent by opening the fresh air system. Compared with the macroscopic effect of 21 naturally ventilated houses tested in the same way, the average indoor formaldehyde concentration of the houses using mechanical fresh air system was 14.3% lower, providing a reference for the winter ventilation mode in Liaoning area.

The effect of street trees on cooling and humidifying can adjust the building microclimate and improve the outdoor thermal environment so as to improve the comfort of human body. In order to study the influence of street trees on the thermal environment of sidewalks, this paper selected the sidewalk of a university campus in Guangzhou for experimental measurement. In this paper, the field measurements include outdoor air temperature, wet bulb temperature, black globe temperature, wind velocity, and ground temperature. The result shows that thermal environment of the sidewalk is related to the trend of street trees and Sky View Factor (SVF). The variation of air temperature between southwest and northeast is more stable than that of east-west sidewalk, the difference between them is below 1 °C, the relative humidity of air is higher than that of east-west, and the minimum difference between them is significant at high shading rate, which can reach 10 °C. The time of receiving solar radiation is shorter than that of east-west direction, and the time of black sphere temperature above 35 °C is reduced by 1–1.5 h. The influence of sky angle coefficient on the thermal environment of sidewalk is as follows: the value of SVF is positively correlated with air temperature and black sphere temperature, but negatively correlated with relative humidity.

Microencapsulated phase change materials (MEPCMs) have been recognized as potential energy storage materials which could be used for reducing energy consumption and improve indoor thermal comfort in buildings. However, current MEPCMs are limited by their singular phase change transitional temperatures and therefore unable to satisfy all year seasonal energy storage applications. This study was therefore focused on numerical assessment of the energy-saving potential of different types of MEPCM drywalls and a binary MEPCM drywall system by ESP-r. The simulation results showed that the laminated binary MEPCM drywall performed thermally better than the other types of walls over a period of the six months. In comparison with the building without MEPCM layer, the binary MEPCM drywall did reduce the peak indoor air temperature by 2.9–6.7 °C and was able to increase about 12% indoor thermal comfort time.

An innovative column attachment ventilation (CAV) was proposed for heating, ventilating and air-conditioning (HVAC) systems, which can directly deliver supply air to the occupied zone without over conditioning the upper zone of the room. The effects of the column layout (i.e. uniform, centralized, dispersed and crossed distribution) in a typical four columns room on the air distribution of CAV were studied through experiments and simulations. Airflow pattern, air temperature distribution, air diffusion performance index (ADPI), and ventilation effectiveness for heat removal were used as the indicators to investigate the ventilation performance. In CAV mode with a uniform column layout scheme, the experimental results indicated that airflow spread over the floor in a radial pattern behaved as a stratified air distribution like displacement ventilation (DV), resulting in an air lake or air pool phenomena in the occupied zone. In the simulation cases, it can be seen that a reasonable air distribution and acceptable indoor environment can be achieved by CAV mode with different column layout schemes. The results indicated that the CAV mode could be an efficient air distribution method and demonstrated the technical feasibility of applying the CAV in the space with different column layout schemes.

In order to explore the thermal comfort of nearly Zero Energy Buildings (nZEB) in cold regions in actual operation, a residential nZEB demonstration building in Shenyang, Liaoning province was selected as the research object. Testing the thermal comfort of the building during winter heating by field investigation and questionnaire survey. A literature survey was conducted on thermal comfort test of ordinary residential buildings in severe cold area over the past decade. We have obtained the thermal neutral temperature based on the statistical regression analysis of data. The results revealed the difference of thermal comfort between ordinary residential buildings and nearly Zero Energy Residential Buildings. In addition, the change law of human thermal sensation and the characteristics of human thermal reaction in nZEB were obtained. Some evidence of thermal adaptation were acquired because of this experiment. It provided references and suggestions for the design and construction of thermal environment of nZEB based on the thermal adaptation of human body.

Past indoor studies show that people’s thermal comfort differ between different climate zones in China. However, whether this phenomenon also applies to outdoor thermal comfort is less understood, which is the focus of this study. We conducted meteorological measurements to calculate the Universal Thermal Climate Index (UTCI) and compared it with thermal comfort survey in Guangzhou and Zhuhai (n = 4283) in September 2018. When UTCI was 28–38 °C (moderate to strong heat stress), the mean thermal sensation vote of local Guangdong respondents was significantly lower than respondents from the cold zone and hot summer, cold winter zone, indicating the influence of acclimatization. The same results apply to respondents who have been indoor with air-conditioning, but not for those who have been in outdoor, exposed environment. Outdoor residency time and thermal expectation in transient environment could affect the difference in thermal perception between Chinese people from various climate zones.

People who live in high-rise residential buildings are seriously exposed to harmful indoor air pollutants due to the lack of ventilation. Our research aimed at investigating the indoor volatile matter pollution status in high-rise residential buildings. From the measurement, some results can be drawn that, first, the indoor mean concentrations of formaldehyde in summer were higher than in winter but opposite for TVOCs. Secondly, the formaldehyde and TVOCs concentration in the bedrooms are about 10% higher than in the living rooms, regardless of in winter or summer. And finally, although in summer, the indoor pollution of the TVOCs and formaldehyde have roughly the same levels, the pollution of indoor TVOCs in winter is more serious and durable than formaldehyde. It is necessary to strengthen the fresh air exchange in existing high-rise residential buildings of China, especially in the sleeping night at bedrooms. And people should choose home products with low or no TVOCs in future purchase.

In the severe cold regions of northeast China, the outdoor temperature conditions are harsh in winter and concentrated coal-fired heating is used, which causes the indoor fresh air requirements cannot be guaranteed in residents in winter. At the same time, as people pay more attention to interior decoration, indoor air quality is receiving more attention. Herein, using spectrophotometric method, GC-MS (Gas Chromatography-Mass Spectrometer) method, TSI DustTrak particle tester and Telaire 7001 CO2 tester, we investigated the concentration change of formaldehyde (HCHO), volatile organic compounds (VOCs) PM2.5 and CO2 of 33 houses for winter under 2 conditions (airtight and natural ventilation). What’s more, the natural infiltration rates of them were also measured by using CO2 as tracer gas in the national standard method. Through the test and long-term monitoring data, the main pollution problem in winter is the indoor TVOC and PM2.5, and the indoor HCHO concentration of the house using the wallpaper in the decoration is much higher than that of other decoration methods. The pollution problem under natural ventilated conditions has been greatly reduced, so residents should open windows more under the conditions allowed by outdoor environmental conditions.

Stratum ventilation with air supply terminal located on the floor level near side-wall is typical for large space building, consequentially resulting in vertical thermal stratification. Heat accumulation in the upper part of unoccupied zone will have significant effect on the cooling load of occupied zone. In order to accurately predict the indoor thermal environment and load characteristics of large space building, and to calculate the heat migration occurring in the thermally stratified environment, the determination of inter-zonal heat transfer coefficient Cb is critical. This paper discusses the method to calculate inter-zonal heat transfer coefficient to represent a large space building. In a scaled laboratory, five experiment cases with different exhaust air flow ratios, heat source powers are studied. CFD simulations of the same cases are performed. The vertical temperature distribution and detailed cooling load results of the entire system and occupied zone are verified based on the experiment results. By dividing the whole space vertically into two and five zones, inter-zonal heat transfer coefficient Cb under different heat source heights is calculated from the CFD numerical simulation results. The results show that the area division method, airflow pattern, airflow state of occupied zone and the heat source affect Cb value.

In this paper, the filtration performance of PM2.5 of eleven kinds of different grades filters commonly used in the Chinese market was tested by experiments for atmospheric dust. The results showed that the arrestance and resistance of PM2.5 at different grades were different. When the filtration velocity of C1–C4 coarse filters were around 1.9 m/s, the arrestance of the filters reached the maximum, and the maximum value of the filtration velocity was less than the range of 2.0–2.5 m/s which was given by the standard. When the filtration velocity was about 0.7 m/s, the arrestance of Z1 medium efficiency filter reached the maximum. For the Z2, GZ1–GZ3, YG1–YG2 grades filters, the smaller the filtration velocity was, the higher the filtering efficiency had. The resistance curve of the filters showed a rising arc, and the relationship between filtration velocity, filtration efficiency, and resistance was analyzed. The filtration efficiency of PM2.5 at various grades of filters and the corresponding filtration efficiency were plotted. The resistance range map provided references for the selection of filters.

The growing tendency of population aging results in the increase of kinds of nursing facilities, and thus thermal comfort in built environment are getting more and more attention. To improve indoor thermal environment for the elderly is essential to a comfortable and healthy life, the key of which lies in scientific and accurate evaluation of thermal comfort for elderly. Field investigations and testing on thermal comfort for the elderly were conducted in Xi’an during winter, spring and summer, a typical city in cold climate zone, China. Both subjective questionnaire survey and objective on-site measurements were carried out, and a total of 835 valid questionnaires were obtained. Based on the analysis of the clothing insulation, thermal sensation, and thermal acceptability against the indoor temperature, and an adaptive comfort model was developed using linear regression. It is pointed out that the neutral temperature for elderly is 20.4 °C, the temperature ranges of 80 and 90% acceptability were 13.8–30.5 and 17.2–27.0 °C. The results of this study may be a useful reference when designing or managing thermal comfortable environment for the elderly in cold climate zone, China.

Radiant cooling/heating systems have advantages of high-comfortability and energy-saving, whereas a certain building usually adopts one type of radiant surfaces (e.g., only radiant ceilings) rather than two or more simultaneously to save initial investment. Radiant ceilings are a kind of common-used radiant systems, which has been widely demonstrated to be effective in summer. While in winter, radiant heating ceilings mainly heat the upper body parts of occupants and the warm air still stays in the upper space of a room. The aim of this research is to produce a better indoor environment of a room with radiant heating ceilings by using side-supply airflow. Four typical conditions were selected to be simulated with ANSYS Fluent. The obtained result showed the system had more uniform air temperature and the air velocity level of was below the 0.2 m/s in most of the occupant zone when two-side-supply airflow and radiant heating ceilings were used simultaneously. In addition, it could create a superior indoor environment by increasing air temperature and reducing air speed.

Evidence from cross-sectional studies all over the world highlights the high prevalence of childhood asthma and its associations with indoor environment. However, different indoor risk factors have rarely been ranked integrated to point out the most significant ones. A cross-sectional study was carried out by CCHH (research on China, Children, Homes, Health) group in Shanghai and 13,335 questionnaires among 4–6 years old children were obtained. Logistic regression model was used to build the associations between indoor environmental factors and childhood asthma. We used the risk assessment framework developed for Global Burden of Disease to estimate attributable fraction and number of cases. The PAF (population attributable fraction) of building characteristics, living and dietary habits, residential materials and renovation was responsible for 26.24%, 39.42%, 34.34% respectively. Dampness, eating milk powder or porridge time, floor materials were biggest in the three categories. Based on the PAFs, we can approximately assess the number of childhood asthma related to living and dietary habits were 68,423 in 2007.

Thermal Response Test (TRT) has become a very popular method of evaluating geothermal properties for ground-coupled heat pump systems. However, a test must be carried out under certain operating conditions of the project it serves, which is a strong restriction to its standardization. Few studies have previously focused on how to deal with TRT results in alternative conditions. Based on line source model, the influences of different factors on TRT results were analyzed, and a new algorithm for correcting TRT results was developed in this paper. The algorithm was applied to a case study, and the results calculated using the new algorithm show that thermal conductivity difference before and after comparison changed from −0.97 W/(m K) to 0.10 W/(m K) at different test conditions, and the relative error between the corrected values of ground thermal conductivity was reduced to 4.63%. Therefore, the new proposed correcting algorithm provides reference to the standardization of TRT and the generalization of test conditions, which can help save test time and cost caused by repeating tests.

This paper summarizes current literature evidence on the associations of indoor carbon dioxide (CO2) with sleep quality and other human responses at dorms, bedrooms or other sleeping environments. Published literature was identified by searching Web of Science and Google Scholar, using the following keywords including carbon dioxide, sleep quality, ventilation rate, indoor air quality, and health effect. From selected studies, detailed findings were summarized based on subjective assessments and objective measurements. The collected data were then tabulated to observe the associations of CO2 concentration with sleep quality and other human responses. Furthermore, the potential confounding of researches was discussed. The results of the reviewed studies show that there was a tendency that lower CO2 concentration improved sleep quality. Given the findings of this summary, effects of indoor CO2 concentration on sleep quality are worthy for further study to elaborate the dose-response relationship between CO2 concentration and human responses during sleep and “no-effect” threshold of CO2 concentration for good sleeping environment requires further research.

As the core means of transportation of modern large cities, the subway provides a good guarantee for the overall development and operation of large cities. But in the process of subway development, the passenger’s thermal comfort has been neglected. There are few studies on subway thermal comfort at present. In this paper, the thermal comfort of passengers was investigated while the thermal environment was tested. The results showed that the temperature of the carriage reached the lowest in the summer, carriage compartment temperature 10 °C lower than outdoor temperature, the average temperature of import, station hall, the platform, and carriage is respectively: 27.9 °C, 27.2 °C, 26.6 °C, and 25.6 °C, respectively. The thermal sensation of passengers generally changes in a V shape, that is, the thermal sensation becomes lower during the arrival process and higher during the departure process, which is similar to the temperature change trend.

In buildings with glazing facades, the uneven distribution of solar heat gain intensifies the asymmetry of indoor thermal environment that might cause local thermal discomfort. But in lots of studies the uneven distribution of solar energy was always ignored. To calculate the specific distribution of solar energy in buildings with glazing facades, the transfer progress of solar radiation was analyzed and a solar energy distribution model was established and the calculating algorithm was programmed in Matlab. The results show that the solar energy’s distribution ratios of interior surfaces are different and the solar energy’s specific distribution on a single surface is asymmetric. For instance, the floor receives 55.8% of incoming solar energy and most of the solar energy concentrates in the area near the glazing. The specific distribution of solar energy changes with time because of the altitude angle and the azimuth of solar radiation.

The valley wind environment is an important part of the study of the street valley microclimate. The wind environment in the street valley has close relationship with the diffusion capacity of pollutants. Its advantages and disadvantages have a direct impact on the air quality in the street valley. The wind environment of the street valley is mainly affected by the geometrical features and flow directions of the valley. In this paper, the influence of the geometric features of the ideal street valley and the flow wind field on the wind environment in the street valley and the diffusion capacity of pollutants are analyzed by the method of computational fluid dynamics (CFD). The result show that vertically flowing down the wind, there is a clear air vortex in the street valley, which is not conducive to the spread of pollutants, and the air quality is poor.

The adaptive thermal comfort model is a model to predict the temperature at which occupants feel comfortable on the premise of considering their adaptability to the indoor thermal environment in naturally ventilated buildings. In the adaptive thermal comfort model, the mean outdoor temperature is an important and unique parameter for calculating the neutral temperature of occupants in naturally ventilated buildings. In this paper, the determination of two important parameters (time constant and time length) in the adaptive thermal comfort model was the focus of this work. A survey was conducted from April to December in 2016 in six naturally ventilated buildings located in Xi’an, China. During the survey, the thermal sensation of the subjects was investigated, and the indoor temperature was measured in the meantime. Based on the field data, the best values of time constant and time length were determined through the correlation analysis. This study provides two reliable values to calculate adaptive thermal comfort model based on the running mean temperature for Xi’an, China.

We analyzed three forms of heating system which is under the similar meteorological condition by testing the temperature distribution of the radiant surface, the distribution of the indoor air temperature in the horizontal and vertical directions, the interior surface temperature of the non-heated surface of the room, and the indoor and outdoor temperature and humidity. The PMV and PPD indexes were used to evaluate the thermal comfort of laboratory in winter. The results show that with other condition unchanged, the human body stands and relaxes and dressed in winter indoor clothes (clothing thermal resistance for 1.2–1.5 clo), the new floor heating room comfortable air temperature would be 17–21 °C, and the optimal water supply temperature is recommended to be 40–43 °C.

When a fire occurs in a tunnel, the flame will be tilted to a certain extent due to the effect of longitudinal ventilation. When the morphological characteristics change, it also affects the combustion and heat exchange behavior. In this study, a scaled test rig with a ratio of 1:6 was established. The variation of the inclination angle of the flame with the wind speed and the source power was obtained under different longitudinal wind speeds. Under the same fire source power, the inclination angle of the flame increases as the wind speed increases. The degree of tilt of the flame is not only related to the longitudinal wind speed, but also to the power of the fire source.

Particle concentration distribution rule in large space building under HVAC system is very important, because that is related to particle removal solution design. This paper mapped particle concentration distribution in a large space factory under stratified air condition system. The results shows that: large particle concentration shows significant variation along vertical direction, with a max difference of 8 times; the highest particle concentration appears at the height of 1.5 m of all particle sizes; relatively low particle concentration appears between 3 and 6 m; and, a relatively high value appears between 7 and 9 m, which seems to tell there is a stagnation zone of large particles at this height. Nozzle side supply air shows better particle spatial remove efficiency than columnar down supply air.

Studies have illustrated that 100,000 people around the world die of asthma due to indoor air pollution every year, 35% of whom are children. Indoor air quality is evidently influenced by building characteristics, such as ambient environment and decoration materials. In this paper, we analysed the relationship between building characteristics and the asthma recovery rate among four groups of children who were selected as the participants in a cross-sectional survey during 2011–2012 (Phase I) and a case-control study during 2013–2014 (Phase II) conducted by CCHH (China, Children, Homes, Health) in Shanghai. Pearson’s chi-square was applied to investigate the significance. The results suggested that the asthma recovery rate was approximately 65% for children living near traffic or a waterfront. Because preschool children are still growing, most recovery rates were over 50%. These findings could attract public attention to building characteristics and provide references for protecting children’s health.

Under the background of current shortage of energy and pollution of environment, efficient control and collaborative optimization strategies for building energy consumption and indoor environmental quality had aroused great concern. However, the optimization of building energy consumption and environmental system was deemed as a comprehensive, iterative, and complex process. There was important practical significance of meeting the upper limit of energy intensity, reducing resource waste and improving indoor air quality. This paper intended to illustrate the research status of optimization strategies for building energy consumption and indoor environment quality by reviewing previous literature taken university building as one targeted building type. The up-to-date main relational technical solutions were summarized for balancing energy consumption and indoor environment quality. Finally, the potential available strategies for optimizing the energy consumption and indoor environment quality in colleges were discussed to meet the requirements of energy intensity limits and indoor environment quality. This study could be a theoretical basis for follow-up researches on optimization strategies for public building energy consumption and indoor environment quality.

China has been experiencing and suffering in a serious air pollution problem these years and has brought air quality into spotlight. Air pollution is a key factor of indoor air quality and has a considerable impact on the public health and indoor occupants’ activities. China still adopts air quality index (AQI) and primary pollutant for assessing the degree of air pollution, which ignore the effects of non-primary pollutants during the same period and the dynamic characteristics of all pollutants. In order to consider the comprehensive impact of various pollutants on air quality, the total air quality index (TAQI) is proposed as an indicator to measure the total air quality. A new index, contribution rate (IAQIP/TAQI), is further proposed as the contribution of a pollutant to total air quality, which may be much different from the chief pollutant. In this study, the daily average values of six pollutants’ concentrations in thirty-one provincial capital nationwide from 2014 to 2017 are used as data sources. According to these indexes, the dynamic characteristic of local air pollutant composition is studied and explored. The indexes proposed in this study have a guiding significance for improving air quality evaluation and help create better indoor air environment in different regions.

Due to the particularity of the function and the use of school buildings, the quality of indoor thermal environment is directly related to the normal development of educational activities and the quality of talent training in schools. So, it is significant to research and improve the indoor thermal environment. In order to understand the present situation of summer indoor thermal environment in school buildings in hot summer and cold winter zone, this paper takes a teaching building in Chengdu as the research object and combines the PHOENICS software to simulate the current situation of indoor thermal environment in summer. And proposed some kind of the energy-saving design strategies such as adopting different types of shading facilities and setting air guide plate. Finally, we analyzed the effect of different optimizations of strategies on the indoor thermal environment of the summer building in the hot summer and cold winter zone.

Thermal comfort in natural ventilated university classroom in Xi’an during transition seasons in autumn (November 2017) and spring (April 2018) was studied in this paper. Field experiments were carried out in the typical teaching buildings in Xi’an Jiaotong University. Indoor thermal environment parameters, including air temperature, black globe temperature, air velocity, and relative humidity, were continuously measured during classes. At the same time, the subjective questionnaires were used to acquire students’ thermal sensation, thermal preference, and thermal acceptability. 1686 valid questionnaires were received. Results showed that the neutral temperatures of autumn and spring are 20.6 °C and 23.2 °C, respectively, while the preferred temperatures are 22.8 °C and 23.8 °C. The thermal acceptability in all the cases measured in both seasons exceeded 80%. Due to the limitation of the adaptation behaviors of the students in classes, the adaptive predicted mean vote (aPMV) model, which is used to determine the thermal comfort in free-running buildings in China, predicts lager comfort temperature zone than the experimental results.

In order to study the characteristics and variation of indoor air environment of office buildings in hot summer and warm winter zone, the indoor air environmental parameters (temperature, humidity, carbon dioxide, formaldehyde and TVOC) of two typical office buildings in Guangzhou were measured year-round, and the comfort evaluation of indoor air environment was conducted subjectively. According to the climatic characteristics, the diurnal variation characteristics of indoor air parameters in summer and transitional season were studied, respectively. Furthermore, the influence of outdoor environment, building characteristics, ventilation and air conditioning system on indoor environment were analyzed, and the improvement strategies of indoor air environment were put forward correspondingly.

With the deterioration of the urban thermal environment, the intensity of the urban heat island effect has gradually increased and the improvement of the urban thermal environment has received increasing attention. As part of the urban green space, the park plays an important role in improving the outdoor temperature environment and alleviating the urban heat island effect. Based on this, the paper studies and analyzes the effect of different landscape types on the outdoor temperature environment in summer parks, and selects four landscape types of Waterfront Greenland, Unshielded Square, Tree-shrub Gove, and Non-waterfront Greenland in the People’s Park and Huanhuaxi Park in Chengdu as the research objects. The air temperature was monitored on-site at different altitudes to 1.5 m in all landscape types, and the effects of different landscape types on the outdoor temperature environment were compared and analyzed. The aim was to seek the best landscape layout of the urban park. The results show that: Waterfront Greenland and Tree-shrub Gove have the best cooling effect, followed by Non-waterfront Green, and Unshielded Square the worst. The maximum temperature and the average temperature of Waterfront Greenland are, respectively, reduced by 2.8–8.1 and 2–4 °C compared with Unshielded Square; the maximum temperature and average temperature of Tree-shrub Gove are reduced by 5.2–5.7 and 1.5–3 °C, respectively, compared with Unshielded Square. The reasonable allocation of Tree-shrub Gove and the proportion of water in the park landscape design can enable the city park to better exert its summer cooling effect and help to reduce the urban heat island effect.

The boiler-room of a large-scale thermal power plant belongs to super-high industrial building. The heat is concentrated in the upper part of the workshop. In the northern cold region, the wasted heat at the top of the boiler-room can be sent to the main plant-floor by the reversal of the roof-fans. The heat which dissipates from internal equipment is used to provide heating in winter, then the self-balanced heating can be achieved in the plant. In this paper, CFD simulation is used to analyze the high-pressure roof-fan reversing condition in the boiler-room. Combined with the airflow organization simulation results, different multiple airflow relay schemes are constructed through simulating the temperature field and velocity field to optimize the layout scheme of the relays of each equipment layer.

At present, China is in a critical period of 70% energy saving in buildings. In order to meet people’s needs for indoor lighting and permeability, the south wall of the same residence in cold region is replaced with the floor-to-ceiling window of Low-E glass in this paper. The realizable k − ε model was used to analyze the influence of outdoor environment conditions on indoor pollutant diffusion process and thermal comfort through different building envelope structure. The results show that the floor-to-ceiling window structure restrains the diffusion of pollutants from the floor at night. After 19 h diffusion, the average concentration value of indoor pollutant in the floor-to-ceiling window structure is 25.7% lower than that of the external wall structure. At this time, the indoor PMV values of the floor-to-ceiling window structure and the external wall structure are 0.14 and 0.05, respectively. And the average indoor temperature of the floor-to-ceiling window structure can meet the requirements of the average indoor temperature of floor heating.

The building simulation method can accurately and conveniently predict and evaluate the indoor environment of the building, thus guiding designers and residents to adopt appropriate ventilation and purification strategies to improve the indoor environment of the building and reduce energy consumption. However, there is no software for simulating the ventilation strategy, IAQ, and purification equipment operation effect. Therefore, this paper independently developed the indoor air quality simulation program-IAQ, and on this basis, put forward the idea and implementation method of IAQ+DeST joint simulation. Finally, a real household in Tianjin was used as a simulation object, and the indoor PM2.5 concentration, CO2 concentration and building energy consumption under natural ventilation, mixed ventilation, and mechanical ventilation were simulated by IAQ+DeST combined simulation method. Calculation. The results show that: First, the relative error between the calculation results of building energy consumption and the results of EnergyPlus calculation is within the acceptable range, thus verifying the reliability of the program. Second, the mixed ventilation method can effectively reduce the building energy consumption under the premise of ensuring indoor air quality and can be considered for application in Tianjin.

PM2.5 can be purified by porous materials beds by the effect of van der Waals force and electrostatic force, but the materials become saturated when the pores in beds are filled. In that case, they lose the ability of cleaning. In relevant references, some methods are proved they can bring out the particles inside the pores including back blowing, heating and immersing the materials in liquid. In this chapter, an experiment system is made to find out the desorption regularity of these methods. At first, the materials in the column catch PM2.5, then desorption process (blowing, heating or immersing alone) begins, during which the pressure drop decreases from the maximum to residual pressure drop and this value reflects the extent of desorption. Results of experiments show that both methods are available. Back blowing and heating can reduce pressure drop of the column and the residual drop becomes lower when air quantity or heating temperature increases until a critical air quantity or temperature is arrived. For immersion, the results show acid liquid has a higher efficiency. According to these conclusions, the recycle of materials becomes realizable, and filters can be more economical.

Numerical analysis for hydraulic transient cavitating flows is quite important for ensuring the safety of pipeline systems such as heating systems and cooling systems. In order to improve the simulation of transient cavitating flows accurately, this paper proposes a coupled hydraulic transient model combined a quasi-two-dimensional (quasi-2D) model with discrete vapor cavity model (DVCM). The proposed model is solved by the method of characteristics (MOC). The features of this proposed model are investigated on simulating transient cavitating pipe flows. Meanwhile, the results obtained by the proposed model are compared with those by the corresponding classical 1D model and the experimental ones provided by the literature, respectively. The comparison shows that the pressure head traces and the duration time of cavities simulated by the proposed model are more accurate than those by the corresponding 1D model. The numerical results computed by the proposed model are in agreement with the experimental ones. It is able to simulate transient cavitating flows accurately in pipeline systems.

China has been facing rapidly growing energy use and severe outdoor air pollution, such as fine particles (PM2.5) and ozone (O3) in recent years. Ambient air could emigrate to indoor environments through openings of buildings, influencing the concentrations of indoor PM2.5, O3, and volatile organic compounds (VOCs) as well as the energy consumption to ensure satisfied indoor air quality. Therefore, air change rate is significantly important in estimating human exposure to air pollutants and energy consumption. In this study, the air change rates in residences without mechanical ventilation system in Beijing, China, when windows were closed and open, were measured. The influential factors were analyzed. The results show that the mean value of air infiltration rate (windows closed) and natural ventilation rate (windows open) for four seasons were 0.31 h−1 and 3.43 h−1, respectively. The air change rates when the windows were closed and open were log-normally distributed, with mean values of −1.77 and 0.76, and standard deviations of 1.02 and 0.88, respectively. Outdoor wind speed, number of floors, type of window, type of building, apartment volume, construction year, and number of rooms had a significant influence on the air infiltration rate. Outdoor air temperature and bedroom volume had a significant influence on the natural ventilation rate.

Based on Delphin software, this paper studies the laws and features of dynamic heat and moisture coupling transfer inside typical composite walls in severe cold regions of northeastern China. Firstly, the numerical model was validated by the experimental data in the literature. On this basis, the wet stability time and its influencing factors, internal water content distribution and ice content distribution within typical composite walls were studied under unsteady environmental conditions. The effect of the initial moisture content on the wet stability time of the composite wall was analyzed. The time required for the composite wall to reach moisture stability is predicted. And the wet stable moisture content of the typical composite wall in the severe cold area is given. Altogether it aims to lay technical support for the analysis and modification of wet accumulation problems, as well as the wall wet risk estimation and evaluation for existing building walls.

Taking the dual-loop organic Rankine cycle of waste heat recovery from diesel engine exhaust as the research object, benzene and cyclohexane were selected as the working fluids of high-temperature cycle, and R134a was selected as the working fluid of low-temperature cycle. Taking the net power output per unit heat transfer area, the mass flow of the working fluids and the net output power of the cycle as the objective function, the influence of the pinch-point temperature difference (PPTD) of the high-temperature evaporator and the low-temperature condenser on the system performance are discussed. The research shows that when the pinch-point temperature difference of the high-temperature evaporator increases, the total net work of the cycle output, the mass flow rate of the working fluid, and the required heat transfer area are reduced, and the net work output per unit heat transfer area is increased. There is a best match between the pinch-point temperature difference of the high-temperature evaporator and the low-temperature condenser. When the sum of the pinch-point temperature differences of the high-temperature evaporator and the low-temperature condenser is 30 °C and 40 °C, respectively, for all selected working fluids, there is an optimal pinch-point temperature difference of the high-temperature evaporator.

A comparative study on thermal comfort of people from buildings with central air-conditioning system (CAC buildings) and split air-conditioner (SAC buildings) was conducted in climate chamber. The experimental conditions covered a wide thermal sensation range from cool to hot, and both physiological and psychological responses were collected. The results showed that the mean skin temperature was significantly higher for subjects from CAC buildings in the non-neutral conditions, while the skin wettednes was no significant difference between the two groups. The subjects from CAC and SAC buildings reported the same thermal sensations, and their neutral temperatures (26.8 and 26.6 °C) and thermal sensitivities (both 0.31 °C-1) were not significantly different as well. The 90% thermal acceptable SET ranges were 24.8–27.4 °C for subjects from CAC buildings and 24.4–30.1 °C for subjects from SAC buildings. The thermal acceptable upper limit was 2.7 °C lower for subjects from CAC buildings. The possible impacts of thermal history and expectation are discussed.

Indoor mould growing on the wall surface can not only degrade building materials, but also endanger occupants’ health. It is of great significance to study the mould growth, especially for domestic research. This paper takes the thermal bridge of building as an example, which is located in Shanghai. Then the hourly temperature and relative humidity were obtained. And the VTT model, MRD model and WUFI-BIO model are used to calculate for assessing the mould growth in one year. From the result, the mould growth in Shanghai is mainly concentrated in summer. The three models evaluate mould growth in different ways. And the VTT and MRD model show that the mould growth time is longer than MRD model in Shanghai. The description of VTT model is relatively straightforward in the result display. Besides, according to the prediction principle, the MRD model covers the wider influencing factors of mould growth.

In order to reduce the pollution of the atmospheric environment, the super large coal storage warehouse has gradually become the main coal storage mode of power plants and other enterprises. However, due to the enclosed structural form, volatile coal dust and coal seam volatile combustible gas concentration is too high, which resulting in increased risk of ignition detonation. Therefore, this paper based on ventilation engineering theory and combined with CFD which focus on natural ventilation used in large diameter (D = 100 m) circular coal storage dome. The impact of opening modes, opening positions and opening size of super large circular coal storage dome on ventilated characteristics were also studied. The designed method of ventilated openings for super large circular coal storage dome is further proposed.

This study aims to investigate the effect of light on visual comfort. Experiments had been carried out in a climate chamber. The experiments contained three color temperature levels (3000, 4000 and 5700 K) and three illuminance levels (100, 300 and 500 lx). Sixteen subjects participated in the experiments. Subjects’ visual comfort was evaluated by questionnaires, including brightness, joviality, color authenticity, relaxation, and alertness. Visual evoked potentials were measured to evaluate the transmission of visual nerve pathways. The entropy method was used to determine the weight of the subjective indicators. The results showed that the light environment of 300 lx and 5700 K color temperature is the most comfortable environment. The latency of P100 was minimal when the illuminance was 500 lx under 3000 K, which indicated the nervous system reflects the fastest in this light environment. This study is beneficial to improving indoor environmental workplace satisfaction.

This research mainly focused on investigating dynamic thermal comfort in transient environments with desk fans. An experiment was conducted during the summer of 2018 in Changsha City. Three step change conditions (34–26–34 °C, 34–28–34 °C, 34–30–34 °C) were conducted with 20 subjects in a chamber room. Subjects can freely adjust desk fans in indoor conditions (26, 28, 30 °C). Thermal perceptions were responded, and physical variables were recorded simultaneously. The results show that overshoot in thermal sensations occurs after temperature down-step change and does not occur after up-step. The steady values of the thermal sensations after up-step change were lower than those in the previous environment before down-step, indicating that thermal sensation is affected by thermal experience before step change. Thermal sensation approached stability more quickly with the desk fan. Air movement preference varied over time and discrepancy occurred between the condition after heating and before cooling exposure. Additionally, desk fans could significantly improve thermal comfort of the subjects after step change.

This study aimed to explore human thermal perception and work efficiency in transient step-changes of thermal environment. An experiment was conducted in three different transient temperature conditions (34–22 °C, 34–26 °C and 34–30 °C). Eighteen healthy subjects were recruited to perform neurobehavioral tests and additional tests to replicate office work. Laboratory experiments were performed to investigate the effects of thermal environment on worker’s productivity. In the meantime, the individual differences in the perception and the complexity of the thermal environment were considered. The subjects filled out the thermal comfort questionnaires for a certain period of time. Finally, a quantitative relation was established between the thermal environment (thermal feeling voting) and the work efficiency of the personnel. The results revealed that thermal comfort caused by high, moderate and low temperature had an impact on workers’ productivity, and under three different transient step-changes of thermal environment, the workers’ productivity was varied at different stages in the short term.

Chinese solar greenhouse (CSG) is an energy-saving production building that is used to grow off-season crops. The north wall of CSG plays an important part to maintain the indoor thermal environment without additional heating during wintertime. To enhance the heat storage/release capacity of the greenhouse wall and improve its indoor thermal environment, an active–passive phase change thermal storage wall system has been developed in this study. This system is composed of 5 concentrating solar air collectors (CSACs), 6 tanks that are embedded in the north wall of the CSG and filled by phase change material (PCM), pipes for linking tanks and CSACs, and a centrifugal fan. During the daytime, the solar energy is collected by the CSACs and then sent into the wall coupled with tanks to store the thermal energy by PCM and increase the temperature of the middle layer. During the nighttime, the energy is released into the indoor environment of the greenhouse north wall passively. By analyzing the air temperature at the inlet and outlet of the pipes, the results showed that the energy of about 8.17–11.52 MJ was stored in the north wall except heat gain through the inner surface for a typical sunny day in winter. Performances of the proposed system were also compared to the ordinary solar greenhouse of the same structure and dimensions. The system enhanced the wall’s heat storage capacity, resulting in an average increase in the CSG’s indoor air temperature, wall surface temperature, soil surface temperature, and daily effective accumulative temperature by 0.86–1.26 °C, 2.03–2.7 °C, 1.36–1.88 °C, and 48.1–55.5%, respectively.

Insufficient fresh air is a common problem in heating rooms, but the supply of cold fresh air not only affects the indoor temperature and flow field, but also causes thermal discomfort and increases energy consumption. The coupling effects of ventilation rate nk on air distribution, heating energy consumption, and thermal environment need deep investigation and research. Taking a heating room as an example, the changes in air distribution and heating energy consumption under different ventilation rates nk are studied in this paper, and the energy-saving ratio, temperature distribution, velocity distribution, and the indoor thermal comfort were analyzed under different operating conditions. The results show that the energy-saving ratio is 9.29% when nk equals 0.5 h−1, and the energy-saving ratio can reach 25.77% when nk rises to 2.0 h−1, but the increase in nk affects the indoor thermal comfort as well. Therefore, the optimal control range of nk is proposed no more than 1.0 h−1. The results can provide a reference for heating engineering applications.

Determining ventilation rates is helpful to study indoor air quality (IAQ). This paper investigated the natural ventilation of three households in Beijing, using exhaled CO2 as the tracer gas to calculate and determine the ventilation rates. Also it considered ventilation conditions in different seasons, in different outdoor air quality, and in different outdoor temperatures. The results show that there are seasonal differences in window opening behavior, and outdoor temperature has a more significant effect on window opening behavior than that outdoor air quality. The data obtained in this study and its analysis is thought useful as a reference source for other studies of energy-saving ventilation systems.

Occupants’ interactions with windows have a significant influence on indoor air quality, thermal comfort, and energy consumption. In residential buildings, window opening duration may vary considerably owing to different indoor and outdoor environmental parameters and personal habits. In order to investigate whether outdoor PM2.5 affects human window opening duration, field measurements were conducted in 14 residential buildings to monitor switch status of windows in living room, bedroom, and kitchen. The results showed that most occupants showed a clear difference in window opening duration among the three main functional rooms in terms of the effect of outdoor PM2.5. The heavy pollution in the non-smog season had a great impact on occupants’ windowing behavior, which reflects that people did not pay enough attention to the mild and moderate pollution in the non-smog season. Combined with the effects of outdoor PM2.5, the bedroom was the best room for the window opening mode. This study reflects unreasonable window opening situation in the living room and kitchen currently.

In order to study the characteristics of ventilation and fire exhaust in spiral tunnels, this paper selects a high-drop spiral tunnel in Yunnan as the research object and analyzes its ventilation characteristics by numerical simulation of tunnel ventilation under different working conditions, using FLUENT software. The results show that, overall, the distribution of ventilation airflow in the tunnel is affected little by the spiral structure of the tunnel. However, in the active area of each jet fan, the longitudinal attenuation characteristics of the wind speed on both sides of the tunnel are not the same. There is backflow of part of the airflow in the tunnel, and there are different degrees of airflow vortex near the fire source, under fire conditions. Compared with the normal ventilation conditions, the fire smoke has a reverse flow length of about 30 m, and the average wind speed in the tunnel under fire conditions is larger, due to the large amount of smoke generated.

This study investigated the comprehensive effects of temperature, relative humidity, and light intensity on sleep quality by the method of objective physiological parameters measurement and subjective questionnaires throughout the whole night. According to the orthogonal experimental design method, nine groups of experimental conditions were obtained by combining temperature (17, 20, and 23 °C), relative humidity (40, 55, and 70%), and light intensity (30, 90, and 150 lx). In each condition, electroencephalogram (EEG) was recorded during the whole night. In addition, subjects reported the questionnaires related to environmental sensation and sleep quality before and after sleep. According to the results which were given by subjective questionnaires and objective data, the indoor environmental parameters have effects on different degrees on sleep quality. Especially, temperature is the main factor affecting sleep quality. Meanwhile, the study also gave their comprehensive optimal conditions, which is the temperature at 20 °C, relative humidity at 55%, and light intensity before sleep at 150 lx and at 30 lx before waking up.

The low-temperature air source heat pump (LASHP) has a promising application future in Western Sichuan, while seldom literature focused on the influence of altitude on indoor temperature. Therefore, the influence of altitude on the indoor temperature distribution for space heating was numerically studied and the influence mechanism was discussed in this paper. The results showed that with the increase of altitude, the indoor average temperature would increase and the temperature distribution could be more uniform in horizontal section. The rising range of the warm air was narrower, and the velocity was slower in vertical section. The temperature stratification in high-altitude areas was not as obvious in low-altitude areas; the difference mechanism was that the heat flow driving force decreased as the altitude increased. It was suggested that the air supply velocity should be reduced appropriately in Western Sichuan. The conclusions could provide a useful reference for the application of LASHP in cold plateau areas.

Fabric is widely distributed indoors. Its porous structure results strong adsorption capacity for volatile organic compound (VOC). The secondary source effect caused by desorption can exacerbate indoor air pollution and prolong the pollution period. Fabrics play a significant role in the VOC mass transfer process indoors. VOC emission is mainly characterized by three characteristic parameters: the initial emittable concentration (C0), the diffusion coefficient (D) and the partition coefficient (K). In this paper, a new model for predicting the diffusion coefficient (D) of fabric is proposed. The model analyzed the multilayer anisotropic interlacing fiber structures comprehensively. A series of environmental chamber experiments were carried out to verify the correctness of the model. Three different types of fabrics (silk, cotton, and polyester) were selected as experimental samples, and formaldehyde was selected as the representative VOC gas. This paper provides a theoretical basis for the accurate prediction of indoor air quality and the design of appropriate control strategies.

Light in the office space is an essential environmental element that has a tremendous impact on the physiology and psychology of the occupants. In this study, the effects of lighting illuminance and color temperature on occupant’s mood were investigated. Two illuminance levels, i.e., 300 lx and 2000 lx, and two color temperatures, i.e., 3000 and 6000 K, were set, creating four experimental conditions. A total of 24 subjects participated in the experiment. Light perception and mood were assessed by questionnaires including PANAS affect scale. The results indicate that positive affect increased under 2000 lx 6000 K and 300 lx 3000 K light. No significant difference in the negative affect was observed. These findings could serve as a predictor of the cognitive performance of employees and would help optimize the working environment according to the specific needs of these workers.

In this paper, fluent software was used to simulate and analyze the influence of three typical ventilation modes on the concentration distribution of fine particulate matter in human respiratory area. A sitting man with breathing was incorporated into the model, and eleven areas of 0.15 * 0.15 m2 were set up to monitor the distribution of fine particulate matter in the respiratory area. The results showed that compared with System 2 (top supply and top exhaust) and System 3 (bottom supply and upper exhaust), the mean mass concentration of fine particles in System 1 (upper supply and bottom exhaust) in the respiratory area was the highest and the maximum value appeared in the respiratory plane at 0.03 m below the nose.

The underground subway stations have become the targets of terrorism due to the features of staff-intensive and poor ventilation. In the present study, the dynamic mesh model was used to predict the dynamic change of the flow field in the tunnel induced by the train motion. The DPM model was employed to simulate the interaction between the continuous phase of the air and the discrete phase of pollution particles. Accordingly, the dispersion of sudden pollutants released in the ventilation shaft was investigated. The results show that the submicron particles have a good following performance with the air. The dispersion characteristics of the particles highly depend on the unsteady flow field in the tunnel, which is significantly affected by the piston effect induced by the train motion. It can be concluded that particle diffusion experiences three stages: vertical forward and reverse diffusion in the wind shaft, vertical positive diffusion in the wind shaft, and longitudinal stable diffusion in the interval tunnel. It hopes that the study can provide guides for future biochemical protection in the subway system.

This paper contains an overview of intelligent heating based on the investigation and analysis of campus buildings of Harbin Institute of Technology. Indoor thermal environment and energy consumption of the Cheku building were simulated under six working conditions in the cold region climate conditions. Based on the calculation outcome of the Cheku building, the energy-saving rate of the Campus I, the Campus II, and the Science Park in heating season are calculated. Results show that the low-temperature heating at night during the semester season can reduce the energy consumption by 5.20%. Low-temperature heating in winter vacation reduced energy consumption by 17.01%. During the semester and winter vacation, low-temperature heating at night can reduce energy consumption by 10.21%. The research results provide a reference for the application of energy conservation and intelligent heating in campus buildings.

Seasonal behavior is an active health behavior to adapt to the changes in climate and environment. This paper studies the influence of seasonal behaviors in consideration of the view of “harmonious with nature”, and then explores it through questionnaires, and experiments. The results of the questionnaire survey show that the region has the most significant impact on the tolerable temperature range, among the influencing factors of gender, age, and region. The acceptable temperature of respondents in the South is 5.7–32.7 °C, and that in the North is 11.0–30.1 °C. Among them, 60% of respondents pay attention to adaptive behavior in their daily lives, and they are mainly influenced by culture. The typical seasonal behavioral experimental results show that seasonal behaviors have a different impact on the different constitution. Subjects with yin deficiency and phlegm-dampness have significantly improved temperature acceptability after drinking mung bean soup and herbal tea in summer. Besides, seasonal behavior also affects physiology. Subjects wearing masks can relieve facial skin hypothermia in less than ten minutes compared to subjects who do not wear a mask. Given the influence of seasonal behavior and constitution, the comfort zone can be multi-dimensional and more targeted. This study is of a significant theoretical reference value for further research of the indoor environment that meets the lifestyle of Chinese people.

In this study, a simulation platform (IAQ-E) is established for integrated study of indoor air quality and energy consumption for ventilation optimization. The platform consists of a natural ventilation module, a mechanical ventilation module, an IAQ model, and an energy model. A residential building in Beijing is simulated, and the IAQ and energy consumption results of various natural ventilation scenarios are compared with mechanical ventilation scenarios. Natural ventilation scenarios consist of having windows 25, 50, 75, and 100% open 2 and 3 times a day for different lengths of time. The mechanical ventilation modes include once in an optimal condition and once in a conventional condition. Results demonstrate that the window opened 25% is the most effective means for the rapid elimination of indoor concentrations of formaldehyde in natural ventilation condition and that using heat recovery mechanical ventilation with filters is more energy efficient during heating season in North China.

The leakage of hazardous gases in the building environment poses a significant threat to the health and even life safety of indoor personnel. It is essential to fully understand the whole process of indoor contaminant dispersion—from source emission, transmission route, to the potential risk of personal exposure. In order to alleviate the harm caused by pollutant leakage to indoor personnel and explore the most effective way to minimize the exposure risk, the airflow pattern and pollutant dispersion features under different ventilation paths were studied in this paper by applying the tracer gas method. The experiment was conducted in a scaled multi-room chamber (1:2). A wind wall system was designed and used to simulate the naturally ventilated environments. Wind velocities at selected key positions which represent the characteristics of multi-room flow field were measured. The concentration distribution was obtained and the possible transmission route of air pollutant was analyzed.

Mean skin temperature (MST) is commonly applied to evaluate human thermal sensation in the uniform thermal environments. However, the skin temperature distribution characteristics in the non-uniform thermal environments were different from that in the uniform environment; the MST calculation method in the uniform thermal environment could not be applicable to the non-uniform environment. So a MST calculation method was proposed for the non-uniform thermal environment in the present study. The human body surface area was divided into 14 parts, and the weight coefficients for each part were given. The MST calculated by the 14 sites method in the non-uniform environment was lower than that in the uniform environment with the same room air temperature. Besides, the MST decreased with the increase of the locally supplied air velocity and the vent size, and with the decrease of the locally supplied air temperature. The MST could be an indicator to the thermal sensation in the non-uniform thermal environments. It is suggested that MST could be calculated by both considering the physiological characteristics and the effect of the thermal non-uniformity.

In order to accurately design a healthy indoor environment, it is important to consider spatial distributions of particles. In this paper, with a simplified passive household as a physical model, the concentration fields of the PM2.5 in displacement ventilation were simulated by CFD, to analyze the influence of smoking and cooking on indoor PM2.5 distribution. Besides, the performance of different supply air parameters on indoor PM2.5 removal was studied. The results show that the two bedrooms suffer less from smoking and cooking activities attribute to the airflow pattern forced by displacement ventilation. In the living room, occupants exposure to higher PM2.5 concentrations with intensive indoor particle emissions. In spite of this, comparative lower particle concentration in the personnel’s breathing zone was shown in the smoking case. Displacement ventilation system with supply air temperature 18°C and airflow rate of 100 μg/m3 has a better particle removal performance.

Window opening behaviors influence natural ventilation and thermal comfort greatly and add huge uncertainty of energy consumption. So, it is essential to propose realistic behavior models. Many researches have been focused on behaviors in dwellings. But there exists big difference between residential and office buildings, and survey in offices should be attached importance. Consecutive monitoring of indoor and outdoor environment along with window opening behaviors in eight offices among four buildings was conducted during May to June 2017 in Harbin. Statistical methods were adopted for results analysis such as logistic regression. The results indicated window operation had notable correlation with indoor air temperature and time of a day. However, window orientation did not show significant impact. Moreover, window opening occurred more often in the morning during a day and probability models were established and validated accordingly. The models enable a better chance of mimicking occupants’ behavior in office buildings.

The CFD software was employed to simulate numerically the indoor airflow distribution in an air-conditioned room with different air supply temperature (20, 22, and 24 °C) and velocity (2, 3, 4, and 5 m/s). The results show that the simulation result is consistent with the experimental data, which shows the accuracy and reliability of CFD software for simulating indoor thermal environment. Specifically, the indicators including temperature, velocity, PMV-PPD, and mean air age are used in the analysis of the differences caused by the varied air supply velocity and temperature on the human thermal comfort. The comparisons show that the optimal air supply condition is the temperature 22 °C and the velocity of 3 m/s.

The air supply mode of artificial environment room was taken as the research object in this paper. The temperature field, velocity field, air age, PMV, and PPD parameters of the air-conditioned room with upper supply and bottom return mode, upper supply and upper return mode, and bottom supply and upper return mode were obtained by numerical simulation. The comfort of the air-conditioned room with different air supply modes was compared and studied. The results show that the bottom supply and upper return mode in the air-conditioned room is the optimum among three air supply modes. This study provides a theoretical basis for the optimal design of air-conditioned room.

Outdoor particulates may penetrate into indoor environments through building envelope even if doors and windows are fully closed, which causes increase of indoor suspending particle concentration and can constitute a potential health hazard. Particulate matter mass concentrations were measured indoors and outdoors at a female dormitory at the end of winter in Harbin, a severe cold city in China. The paper aims at on-site test research of PM2.5 penetration characteristics through students’ dormitory building envelope, by observing indoor–outdoor PM2.5 concentrations, the indoor–outdoor ratios were obtained, and then the dynamic model was utilized to calculate the average penetration efficiency, the average particle deposition rate and the average infiltration factor. In this study, we utilize methods for determining penetration efficiencies for particles and investigate the relationship between penetration, deposition and the concentrations of airborne particles indoors and outdoors. The case study may provide practical reference for the overall particulate penetration research in civil buildings in China.

A cross-sectional study data about building dampness indicators and perceptions of undesirable odors and child’s asthma and allergy symptoms were collected by means of a questionnaire in the urban area of Harbin, China. A total of 2600 families with children 2–8 years old returned completed and effective surveys. The most frequently self-reported symptom was sneezing without cold or flu (41.8%); condensation on windowpanes (43.9%) was indication of high relative humidity indoor air combined with cold surfaces; residents were more unsatisfied with the smell in the air during the last three months than the newborn period. Perceived dampness was the important risk factor for children’s health outcomes during lifetime-ever and during the last 12 months. Most of the dampness indicators and perceptions of odors were significantly associated with child’s asthma and allergy symptoms. Indoor dampness indicators were risk factor for the rhinitis and sneezing without cold; similar results were found in the undesirable odors analyses, and they were risk factors for the rhinitis, wheezing, allergy, and eczema. In spring and summer, the occasional ventilation had certain inhibitory effect on the asthma, but in spring, frequent ventilation was a risk factor for asthma. Ventilation is an effective method for removing or diluting indoor potentially harmful pollutants.

Radiance simulation of the daylight illuminance distribution with prismatic daylight redirecting fenestration (Micro-prism film and Prismatic panel system) is adopted in this study. This study analyzes advantages and disadvantages of the daylight environment with prismatic daylight redirecting fenestration which is applied to the classroom façade windows. Daylight environment performances with the prismatic daylight redirecting fenestrations at various solar altitude angles are simulated and analyzed.

Kang heating mode at rural houses in China is quite different from central heating system in urban areas. The relevant conclusions drawn from the research on thermal comfort of urban residential buildings are not applied to rural houses. It is necessary to study indoor thermal environment and thermal comfort at rural houses in China. A field study was conducted in winter at rural houses in the severe cold area, China. The environmental parameters and the occupants’ subjective thermal responses were collected simultaneously. The measurement results show that the mean indoor air temperature at rural houses in winter was 15.7 °C, much lower than that of 24.3 °C in urban residential buildings with central heating system. The neutral operative temperature was 17.9 °C, much lower than that of urban residential buildings, which was 23.5 °C. However, according to the subjective questionnaire, about 95% of the rural residents considered that the thermal environment was acceptable, and nearly 90% of the residents felt comfortable. Kang can not only increase indoor air temperature but also the indoor radiation temperature. Therefore, occupants feel comfortable in Kang environment. Kang has a long history and a huge cultural accumulation, which is a very suitable heating mode at rural houses in the severe cold area.