Sustainability in Energy and Buildings

This paper is to present a case of a newly built office building in the UK and to show how the energy efficiency technology in building might contribute to the energy conservation and therefore in full compliance with Part L building regulation. A large array of solutions are used which include the use of ventilation system with good high heat recovery system, limiting the heat loss and gain through the fabric by enhancing levels of insulation of building fabric to achieve lower u-values, limiting the heat loss and gain through the fabric of the building by improving air tightness to minimise any uncontrolled air leakage, provision of space heating and hot water systems which are energy efficient, improve daylight levels and reduce artificial lighting energy, provision of lighting control systems with appropriate lamps so that energy can be used efficiently improve control and monitoring of mechanical heating and ventilation systems. The office building in case study has shown the compliance with the building regulation and thus conserves the energy. Energy conservation and the compliance with building regulation are achieved through early incorporation into the building design.

The thermal performance of the building envelope is an important requirement for guaranteeing both a comfortable indoor climate and building’s energy efficiency.

Ventilated facades and ventilated roofs could be considered as a passive cooling system that contribute to realize low energy building.

The energy advantages provided by the ventilation of structures, during the summer, is the reduction of the cooling load due to the combined effect of the shading of the external wall and the heat removed by the air flow rate in the ventilated duct.

The objective of this study is to evaluate, the effects of the pitch angle, the intensity of solar radiation, size and shape of the cavity, on the thermal behaviour of ventilated roof. The results show the amount of the Energy Saving obtainable by the ventilation of the roof.

The adaptations people utilize in response to ambient physical environmental variations are critical factors for the thermal comfort of occupants in real environments. From the adaptive point of view, thermal comfort is not solely dependent on physical thermal stimuli, but involves complex interactions between the occupants’ adaptations to the physical environmental stimuli and socio-economic-cultural issues. Under certain circumstances, the adaptation of occupants to their environment may be affected by physiological, behavioural and psychological factors. The interaction of the three adaptations further affects the extent of the thermal comfort the occupants finally feel. This paper introduces a method for the evaluation of the weight of contributions of three categories of adaptations to attain thermal comfort in office environments using the Analytic Hierarchy Process (AHP). The AHP is an ideal tool for decision-making where multiple factors are involved. Through solving a pairwise comparison matrix, the weight of each adaptation category can be produced. This paper aims to develop an empirical occupants’ adaptation-based thermal comfort model for office environments. The feasibility and validity of such the model has been verified by a pilot study.

Many of the existing buildings constructed mostly with natural raw materials, in European sites, are frequently lacking proper maintenance and, therefore, a high degree of degradation is verified in these buildings compromising their integrity and reducing their lifetime probability. Often in the rehabilitation or reconstruction of old buildings the solution adopted is the partial or integral demolition and substitution of several building components. The aims of this study are to describe the most common constructive solutions in Portuguese buildings constructed with raw natural materials, to specify the principal problems that affect each building component, and to present possible solutions to correct each defect. This study is focused on the principal elements that compose the building structures in Portugal, including load-bearing walls, wooden floor and roof structures. The architecture solution, the structure solution, the building material’s identification/characterization, the sequence of structural failures and the main pathologies identification/characterization related to an early XX century Portuguese watermill were described and detailed. It may be considered as a real scale experimental model which may contribute to the rehabilitation and conservation fields of traditional Portuguese buildings. The structural failure sequence was analyzed, the corrective solutions presented and studied privileges the adoption of materials and techniques similar and most compatible with the original ones. It’s also presented the structural solution savings of energy consumption and CO₂ emission. The results of this study were found to be easily extrapolated to the repairing of the Portuguese traditional buildings which are in general environmental friendly.

Abstract. The concept of a ‘whole house’ is rarely applied to individual dwellings because each is generally regarded as a loosely connected collection of standalone systems that are provided by different manufacturers with hardly any account being given to interconnectability within the overall concept of a house as a single entity. Most houses have very basic systems for the control of major energy sources including heating and lighting. Electronic control systems requiring only basic skills to install and service can give occupants an ongoing overview of their energy use and facilitate minor changes in habit / lifestyle to allow further savings. The effects and lifetime of these control systems will be improved if they include the ability to be reprogrammed by the user to take into account future improvement projects such as upgrades in insulation or the fitting of double glazing or a change in energy supply. Lifestyle and occupation patterns will have a major effect on energy saving within domestic premises. Any proposed system must be adaptable to suit different living patterns. Interfaces between various components therefore need to be as simple as possible to allow ‘mixing’ of different technologies and possible future developments. It is concluded that a whole house control system that is practical, cost effective, future proof and easy to use is viable but that it could not utilise a single processor design. Instead, a hierarchical system is proposed that presents the possibility of a simple, future proof whole house control system that will accept inputs that are not specified at the time of installation.

A Courtyard in a building regulates its daylight, air movement and thermal interaction with the outdoor environment. The daylight performance of a courtyard depends principally on how the daylight received and delivered into interior spaces. The current research investigates how courtyards vertical surface geometries could improve the daylight in adjacent spaces of the courtyard. The research used Radiance to investigate the impact that vertical walls, inward sloped walls, outward sloped, staggered walls and double layer walls could have on both daylight quantity and quality. Courtyards with inward sloped, inward staggered and double layer walls were found to improve the daylight quality and control the excessive light level, while outward sloped and outward staggered walls increase daylight level.

The rural housing reconstruction and new construction are proceeding all over the country in northern China, but there is still so much high-energy consumption on rural housing. The rural housing may contribute to reduce energy consumption. The method of questionnaire survey to Heilongjiang Province is offered to recognize the housing current situation. The study found various influence factors of high-energy consumption. This paper presents proposal to improve the consumption of rural housing in northern China. It is suggested that energy conservation in residential buildings must be considered all-around, rather than any resolution in only one direction.

This paper takes Heilongjiang province, the coldest province in China, as an example to study one energy-saving rural housing form which is suitable for rural areas in Heilongjiang province. In order to make the rural housing becomes more comfortable, healthy, energy efficient and environment friendly. Through the calculation of the computer software, this energy-saving and sustainable housing which is built according to this research can reduce the energy consumption by 53.4%. This will promote the sustainable development of rural housing in the severe cold region of China.

One of the heat transfer mechanisms in the cavity of the hollow concrete block is the natural convection. The cavity formed by concrete blocks placed in walls, has a geometric ratio of 20:1 for common blocks of 0.1 m width. The thermal gradients applied are representatives of the boundary conditions in a wall exposed to weather conditions in a desert climate. Experimental and numerical convective heat transfer coefficients are presented and compared. The numerical flow and temperature pattern, obtained with CFD software Fluent 6.3 are discussed.

This paper presents a method to regulate the power frequency at a nominal value using a battery energy storage system (BESS). A control system model is proposed to simulate the BESS for frequency control application. A controller based on model predictive control (MPC) is designed for the optimal operation of the BESS for primary frequency regulation. A frequency prediction model based on Grey theory is also designed to optimize the performance of our controller. The method is tested using real measurements from a real power grid in the presence of multiple and realistic physical system constraints. The effectiveness of the proposed frequency regulation scheme is demonstrated with a simulation example.

Since energy production is no longer limited to decentralized systems, but brought into the urban environment, where a huge amount of energy consumption takes place, new technologies are emerging and already known technologies are used in another context. One of these technologies is wind energy. Even though the wind energy is significantly lower in urban districts wind turbines are currently erected and new design of wind turbines could possibly be designed rather cost effective. Several trials and studies in different countries were conducted, where small-scale wind turbines were attached to building walls or mounted on rooftops [1, 2, 3, 4]. The used wind turbine configurations were various, including lift-driven horizontal axis wind turbines, drag-driven vertical axis wind turbines, but also completely new concepts. One essential part for a promising integration of wind energy in an urban context is a well designed wind turbine; well designed for the wind condition it is going to be exposed to.

This paper describes the significance of empirical direction dependent power curves for wind power prediction at a wind farm site. The results, based on empirical studies, demonstrate that use of directional power curves for wind farm power prediction can lead to an accuracy improvement in the final power prediction of the wind farm. In general, the influence of wind direction on power output is less significant as compared with wind speed due to the fact that turbines are directed to face the wind during its operation. However, maximum wind power potential could not be achieved due to the specific site conditions and important factors like wake effects, environmental effects, hysteresis, and curtailments in the wind farms. Therefore, it is important to model the local conditions of the wind farm; directional power curves are one of the techniques to maximize the expected power production. This case study is based on real-world measurements from a selected wind farm site in Australia.

The on-going adoption of biofuels is presenting problems for automotive diesel engine systems, due to the differing mixture preparation and combustion properties of the widely varying fuel blends in the vehicle tank. Diesel engine management has improved enormously, yet it still relies largely on look-up tables and ‘reactive’ exhaust treatment technologies. ‘Intelligent Fuel Characterization’ facilitates a ‘proactive’ engine management role by gathering, processing and making available information about the precise fuel blend which is about to be combusted in the engine. The engine management system can then use this information to optimise engine system operating points for the exact blend of fuel. This paper introduces the concept of Intelligent Fuel Characterization and presents ideas for its implementation, including promising sensor and data analysis technologies.

The battery charging performance in a stand-alone solar PV system affects the PV system efficiency and the load operating time. The New Energy Center of National Taiwan University has been devoted to the development of a PWM charging technique to continue charging the lead-acid battery after the overcharge point to increase the battery storage capacity by more than 10%. The present study intends to use the super-capacitor to further increase the charge capacity before the overcharge point of the battery. The super-capacitor is connected in parallel to the lead-acid battery. This will reduce the overall charging impedance during the charge and increase the charging current, especially in sunny weather. A system dynamics model of the lead-acid battery and super-capacitor was derived and the control system simulation was carried out to predict the charging performance for various weathers. It shows that the overall battery impedance decreases and charging power increases with increasing solar radiation. An outdoor comparative test for two identical PV systems with and without supercapacitor was carried out. The use of super-capacitor is shown to be able to increase the lead-acid charging capacity by more than 25% at sunny weather and 10% in cloudy weather.

Using off-peak electricity for domestic loads instead of burning fuel can reduce CO₂ emissions. Two loads are considered: electric vehicles, which displace petrol and diesel, and electric space and water heating, which displaces natural gas.

The paper uses experimental evidence based on case studies, together with estimates based on existing information, to calculate the extra electricity demand which might result from changing to electricity. The resulting figures are used to estimate how much demand could be met without reinforcement of the distribution infrastructure, and what reinforcement might be needed if all the demand is to be met by electricity.

It is shown that charging of electric vehicles can be accommodated, in most cases without reinforcement of the distribution network. However, electric domestic space and water heating would require reinforcement, unless very stringent efficiency improvements can be achieved.

A Micro-Trigeneration system based on Karanj Methyl Ester-Diesel Blend fuelled CI engine is designed and realized in laboratory. Experimental investigations are carried out to evaluate the performance and emissions of the original single generation system as well as the Trigeneration system developed. The test results show that the total thermal efficiency of Trigeneration reaches to 87.28% at the engine full load compared to only 33.21% for that of the original single generation. CO₂ emission in kg per unit (kWh) of useful energy output from Trigeneration is 0.1348 kg CO₂/kWh compared to that of 0.3184 kg CO₂/kWh from single generation at the engine full load. Percentage reduction in CO₂ emissions in kg/kWh with Trigeneration as compared to single generation throughout the load range is from 57.65% to 87.37%. The experimental results show that the idea of realizing a Karanj Methyl Ester-Diesel blend operated Micro-Trigeneration is feasible and effective to utilize the resources more efficiently.

First, we analyzed available data on renewable energy consumption and the share in the European Union, taking 2005 data, total and per capita general energy consumption and per capita income during 2000-2006 as references. Afterwards, a nonlinear methodology for territorial distribution of the EU-27 goal for reaching a 20% share of renewable energy in the gross final consumption of energy is proposed. This methodology is applied to the year 2020 on the NUTS0 territorial level, that is, to members of the European Union, according to the EUROSTAT Nomenclature of Territorial Units for Statistics (NUTS). Weighting is done based on the share of energy from non-renewable sources in gross final consumption of energy, energy from non-renewable sources per capita, energy from non-renewable sources per GDP and GDP per capita. Finally, a multicriteria formula was applied, weighting the variables used in this study.

This research investigates ‘best practice’ design and decision-making processes for achieving sustainable buildings and communities over the long-term. Amongst the core objectives of strategic urban planning for sustainable communities is to accommodate future changes, however this is not explicitly integrated into the planning and design processes. A framework of future-proofed building design is proposed, which aims to bridge the gap between the traditional shortterm outlook and the need for resilient and flexible buildings over the long-term. An overview of design principles for sustainable urban communities and buildings within them is followed by an examination of decision-support techniques and tools. Insights regarding how new developments should address these objectives are captured. The research represents a shift away from the short-term mindset that still dominates design and construction practices, and provides a critical review of assessment methods for improving and incentivising sustainable urban design over the long-term.

Current approaches to the design and planning of new housing developments in the UK do not sufficiently contribute to the necessary carbon emission reductions that will be required to meet UK Government targets and to avoid dangerous climate change. A tool (the Climate Challenge Tool) has been developed, which allows house builders to calculate whole life carbon equivalent emissions and costs of various carbon and energy reduction options for new developments. These cover technical and soft measures; energy used within the home, energy embodied in the building materials and emissions from transport, food and waste treatment. The tool has been used to assess the potential of various carbon reduction options for a proposed new housing development in Cambridgeshire. It was found that carbon reductions can be achieved at much lower costs through an approach which enables sustainable lifestyles rather than one which purely focuses on reducing heat lost through the fabric of the building and improving the heating and lighting systems. Furthermore a triple-bottom line analysis shows additional social and economic benefits from many of the measures.

Refurbishing existing buildings to reduce greenhouse gas (GHG) emissions is important in meeting Australian government aspirational targets of a minimum of 25% by 2020. Previous studies of such refurbishments tend to provide only general upgrade, cost and investment advice because they apply generic building attributes and location criteria. They also ignore life cycle aspects such as component assets being replaced at the end of their service life and sustainability investments are over-and-above these ‘normal’ investments. This research investigates an appropriate methodology for more realistic evaluations of refurbishments and life cycle investment to upgrade buildings to 5 to 6-stars on the NABERS Australian energy rating system. The methodology is presented and discussed as a suite of inputs, simulation tools, and outputs. Preliminary results from ongoing work illustrate the outputs and their interrelatedness.

This work focuses on façade improvements because they can have a major influence on the energy consumption and upgrades based on HVACs alone are often insufficient in achieving the required energy savings.

‘Sets of improvements’ are introduced as a means of controlling the variables by way of façade improvements and related changes to mechanical and electrical systems required because of the interconnectedness of building envelopes and these services.

By 2050s the UK is expected to experience: increase in average summer mean temperatures (predicted to rise by upto 3.5 ^o C) and frequency of heat-waves / very hot days; and increases in winter precipitation (of up to 20%) and possibly more frequent severe storms. Also, in 2050s approximately 70% of UK buildings will have been built before 2010, which due to aforesaid climate change factors will suffer from various types of obsolescence – including energy related obsolescence. Thus, if sustainable built environment is to accommodate climate change and the investment in these buildings (which was approximately £129 billions in 2007 in the UK alone) is to be protected, action needs to be taken now to assess the vulnerability and resilience of the existing UK built environment; and plan adaptation / mitigation interventions, that allow to continue to support the quality of life and well-being of UK citizens. The situation with other countries around the globe is not dissimilar, although there may be some variation in nature and quantity of climate change, and the way climate change impacts manifest themselves in relation to the resources and governance of a given country. Failure to act now will mean that the costs of tackling climate change in future will be much higher, jeopardising not only environmental but also economic sustainability. In view of these concerns, this paper will focus on obsolescence that is associated with energy and climate change. The climate change factors that shall be specifically covered include global warming, flooding, carbon emissions, carbon cut targets, environmental legislation and building regulations. Obsolescence types are categorised into direct and indirect obsolescence groups. Moreover, although the paper will mention both generation and consumption of energy, the later shall be more specifically addressed due to accelerating demand of power as well as pressures for efficient energy consumption in buildings to cut carbon emissions. Finally, in light of to date literature review, the paper will emphasise requirement of a fundamental framework for identification and categorisation of energy related obsolescence in the built environment, which shall attract interests for further investigation from both researchers and practitioners.

This paper describes the Greek hoteliers’ attitudes about energy initiatives and their implementation to their facilities. The aim of this paper is to demonstrate the interaction between the users’ behaviour and the way energy is consumed in Greek hotels in a long-term period. This paper is part of a wider research project that explores the energy consumption in several Greek hotels. Through interviews with open-ended questions, their responses reveal their opinions and the level of information they have on the existing legislation-Greek and European- on energy use in buildings. Further than that, two scenarios are developed, using the Long Range Energy Alternative Planning software (LEAP). Each one of them exhibits different findings proposing significant but easy to apply alterations to hotels. The first one is the Business as Usual scenario, and it is developed based on the current trends in energy use in hotels. The second is the Policy scenario which is developed based on the existing legislative framework, Greek and EU.

Wireless sensor networks provide a new way of working for applications such as indoor monitoring, security or robotics. The Ecosense project aims to monitor all devices consuming energy in an intelligent building. We are developing this project in steps. Firstly, we have deployed a network equipped only with sensors (for temperature, humidity, luminosity, and electrical consumption, as well as presence detectors). Secondly, we will add an upper layer of manager agents (actors) to communicate and negotiate services. Afterwards, we will obtain conclusions about the sensed data and we will then extend a full wireless sensor network to cover the whole building. The network prototype will also be used to test power-and-time efficient protocols developed by us.

In the UK the existing domestic building stock accounts for 30 % of the total carbon dioxide emissions [Domestic energy fact file, BRE, 2008]. The UK Government has set ambitious targets for reducing UK carbon dioxide emissions by 80% by 2050. These targets will require significant changes to the existing buildings. To understand and quantify the benefits of refurbishment solutions, it is vital to monitor exemplar buildings and to bring them to an energy efficiency standard with lower associated carbon emissions, by finding the most efficient way to refurbish them. A 1930’s replica three bed semi-detached house analyzed in this study is located in the University of Nottingham campus and is fully monitored, including monitoring of the occupants patterns, environmental monitoring, electricity use and energy associated with space and hot water heating. This paper analyses techniques used for tracking computing technologies in everyday domestic settings. A Real Time Occupancy Monitoring System using ultra wideband (UW) radio frequency (RF) is used in this study to track person’s location within the research house. The results presented in this paper shows that energy consumption profiles are related to the occupants and their profiles. The data also depends on the outside weather conditions and occupants’ behaviour. The study shows that it is not enough just to improve building performance in order to improve energy efficiency; it is also important to understand and influence occupant behaviour, due to the fact that in domestic buildings the occupants exert complete control of the appliances, lights, heating, and ventilation. The results of this study suggest that general behavioural trends and patterns can be extracted from long-term collected data. This systematic study could benefit the existing housing stock in the UK by applying the same methods used in the research house.

The production and use of energy are the cause for the 94% of CO₂ emissions, with an important share, at least 45%, corresponding at the building sector. Buildings are accounting for the 40% of energy consumption in Europe, while the increase of demand of electric energy is forecasted to reach up to 42% at 2020. Greek buildings absorb roughly the 1/3 of consumed energy and emit the 45% of CO₂. Particularly, the tertiary sector represents roughly the 25% of total number of Greek buildings. The category of offices/commercial buildings constitutes the higher percentage between the main categories of tertiary sector and it represents the 2.74% of total building reserve, that corresponds at a total energy consumption equal to 339 kWh/m².

In this paper, the energy behaviour of public buildings is studied. The energy situation of public office buildings in the prefecture of Florina, in North Greece is investigated. The paper demonstrates the energy assessment of office buildings and it formulates proposals for the improvement of their energy efficiency. The evaluation of the existing energy situation and the proposed energy interventions was performed with the EPA-NR software,

The parameters that were taken into account were the constructional data of the buildings, the data on the operation of the buildings, energy consumption and the exterior climatic local conditions.

This paper details the modelling and prediction of the solar energy supply available for hot water and space heating in a domestic house designed to ‘zero carbon’ standards in the UK Midlands. The design strategy for the dwelling includes a highly insulated timber frame fabric with a south-facing full-height sunspace and ‘low-U’ glazing to optimise natural lighting and solar energy gain over the year. A solar thermal system installation is intended to further reduce fossil energy consumption. In conjunction with post-occupancy evaluation, a computational whole-building model with sub-systems has been configured to represent and evaluate in detail the integrated system energy performance including domestic hot water and space heating requirements.

The integration of concentrating solar thermal collectors into the structural envelope of buildings can significantly increase the cost effectiveness of solar thermal utilisation in the UK. The key, however, to their wide scale application is performance. Typically, most solar thermal collectors are mounted on inclined roof structures, thus presenting an optimal surface area for solar gain. Vertical building facades offer an alternative mounting surface and whilst they may have an overall lower level of incident solar radiation, the collector receives a more uniform annual distribution of solar radiation, reducing potential summer over heating problems. Furthermore, facade integration is beneficial to the building performance as the collector unit results in a higher U-value realising higher building heat retention.

In concentrating solar thermal collector systems, the absorbing surface area is reduced relative to that of the aperture, leading to a reduction in the overall heat loss from the system, hence improving thermal efficiency. To maximise collection in a vertically mounted concentrating solar thermal collector however, the concentrator profile should be optimised to benefit solar collection relative to the mounting inclination.

This paper presents the optical and experimental investigation of a low concentration line axis solar thermal collector employing symmetric and asymmetric CPC geometries. The potential for collected solar radiation when façade integrated has been investigated with the use of three-dimensional ray trace. Several prototype units were fabricated and experimentally evaluated. A series of fluid flow configurations (serpentine and parallel) using different flow velocities have been investigated and a range of slope angles (β) considered.

Results from this study have shown that this type of concentrating solar thermal collector has particular application for domestic hot water production and that the design can effectively operate in the vertical orientation and is suitable for building façade integration in Northern European locations.

Photovoltaic (PV) can supply all or a significant part of the electricity consumption of a corresponding building without depletion of finite fossil fuel resources. They can be mounted on buildings’ roofs or facades. Energy production in buildings by renewable energy sources has recently gained importance and has been referred in laws and regulations regarding energy efficiency policies. Although Turkey has one of the most solar electricity generation potential in Europe, there are only few PV applications in buildings. These examples include mostly PV systems mounted only on low-slope roofs as alternative constructional designs are still unknown in Turkey. Moreover, there is not a guide, regulation or standard regarding the construction of PV roof systems. In order to assists architects, constructers and roof covering material producers to develop correct design alternatives, a model has been developed for the constructional design of PV roof systems. The aim of this paper is to present the model proposed for the design of PV mounted steep roof systems and based on the model, a case study in which a PV mounted steep roof system is designed for Istanbul, Turkey.