6.1 Scope of Application of Attachment Ventilation Systems
6.1.1 Distinguishing Features of Attachment Ventilation Systems
6.1.2 Occupied Zone
Building envelope  The boundary of the occupied zone (m)  

Displacement ventilation  Attachment ventilation  Mixing ventilation  
Wall/column surface where diffusers are located  0.5–1.5  1.0  1.0 
Exterior walls, doors, windows  0.5–1.5  1.0  1.0 
Interior walls, column surfaces without inlets or openings  0.25–0.75  0.5  0.5 
Floor  0.0–0.2  0.1  0.0 
Distance from floor to top  1.1*–2.0**  2.0  1.8 
6.1.3 Airflow Parameters and Diffusers in the Occupied Zone

For ordinary office and residential buildings, u_{n} ≤ 0.2 m/s for winter, u_{n} ≤ 0.3 m/s for summer.

Regard to temporary staying zones, e.g., railway stations, subway stations and airport terminals, etc., u_{n} ≤ 0.3–0.8 m/s; for industrial buildings, e.g., underground power plants, etc., u_{n} ≤ 0.2–0.8 m/s.

Air velocity in the control zone can also be determined according to the needs of production processes.

For ordinary offices, residential buildings, etc., u_{m,1.0} ≤ 0.5 m/s.

For temporary staying zones, u_{m,1.0} ≤ 1.0 m/s.

For industrial workshops, according to the needs of the industrial manufacture process.

The inlets or openings should not be laid on the exterior wall or the wall with a window.

There should not be protruding obstacles on the jetattached wall.
6.2 Attachment Ventilation Design Procedure

C = shape factor, C = 0.0075 for vertical walls; C = 0.0180 for rectangular columns; C = 0.0350 for circular columns.

K_{h} = Correction factor, \(K_{{\text{h}}} = \frac{1}{2}\frac{h  2.5}{b}\) for vertical walls and rectangular columns; \(K_{{\text{h}}} = \frac{1}{6}\frac{h  2.5}{b}\) for circular columns.
6.3 Adaptive Attachment Ventilation Design Procedure
6.4 Comparison of Design Methods of Attachment, Mixing and Displacement Ventilation
Type  Mixing ventilation, downward air supply (Zhao 2008)  Attachment ventilation  

Design scheme  A diagram of mixing ventilation air supply denotes the direction of flow from the jet mixing to the occupied zone in a clockwise manner. The gap between the occupied zone and the left wall is 1.0 meters and between the right wall, it is 0.5 meters.
 A layout for displacement ventilation has an occupied zone and different dimensions. It has two decreasing to increasing lines at the bottom side. The gap between the occupied zone and the left wall is 1.0 meters, and the right wall is 0.5 meters.
 A layout for attachment ventilation has an occupied zone in the middle along with other dimensions. The occupied zone has a height of 2 meters. The gap between the occupied zone and the right wall is 0.5 meters. The flow is directed from top to bottom.

Load  Mixing ventilation bears the whole cooling/heating load, while displacement and attachment ventilation only bear part of the load (occupied zone load)  
Known condition  Room size L × W × H (length × width × height), excessive heat Q, indoor design temperature t_{n}  
Design procedure  ① Calculate air supply rate according to indoor excessive heat and air supply temperature difference (generally, t_{n} − t_{0} should not be greater than 10 ℃ for comfortoriented air conditioning) \(q_{{\text{s}}} = Q/[\rho c_{{\text{p}}} (t_{{\text{n}}}  t_{0} )]\) ② According to the air supply rate and room size, determine the diffuser form and size, derive the number of diffusers N and spacing r, calculate the single diffuser area F and air supply velocity u_{0} ③ Calculate jet throw x: \( x = L  \, 0.{5} + ({\it\text{H}}  {2}.0)\) ④ Check the jet velocity as it enters the occupied zone u_{m,x}, \(u_{{\text{m,x}}} = \frac{{u_{0} Km_{1} \sqrt {kF} }}{x}\) (Zhao 2008) If u_{m,x} ≤ 2u_{n}, it meets the design requirements. Otherwise, go back to step ② to rearrange the diffusers ⑤ Design parameters, including u_{0}, t_{0}, diffuser size and location, number, etc. are obtained  ① Determine the basic indoor control parameters t_{d−1.1}, Δt_{g} ② Assume the dimensionless temperature rise near the floor \(\kappa = \frac{{t_{0.1}  t_{{{\text{m}},1.0}} }}{{t_{{\text{e}}}  t_{{{\text{m}},1.0}} }} = 0.5\) ③ Calculate the temperature difference between supply and exhaust air: \(t_{{\text{e}}}  t_{0} = 2h_{{\text{e}}} \Delta t_{{\text{g}}}\) ④ Derive air supply rate q_{s} and air supply temperature t_{0} \(q_{{\text{s}}} = Q/[\rho c_{{\text{p}}} (t_{{\text{e}}}  t_{0} )]\) \(t_{0} = t_{{{\text{d}}  {1}.{1}}}  \Delta t_{{\text{g}}} \left( {h + {1}.{1}} \right)\) ⑤ Check the temperature at floor level t_{0.1}: t_{0.1} ≥ 22 ℃ for summer ⑥ Obtain the inlet opening area F and determine the number N of diffusers: \(F = q_{{\text{s}}} /\left( {{36}00 \times u_{0} \times N \times k} \right)\) ⑦ Design parameters, including u_{0}, t_{0}, diffuser size and location, number, etc. are proposed  ① Determine indoor control parameters: t_{d,1.1}, Δt_{g}, Q_{n}, h, h_{e} ② Assume the dimensionless temperature rise near the floor: \(\kappa = \frac{{t_{0.1}  t_{0} }}{{t_{{\text{e}}}  t_{0} }} = 0.55\) ③ Determine the exhaust air temperature t_{e}: \(t_{{\text{e}}} = t_{{{\text{d1}}.{1}}} + \Delta t_{{\text{g}}} (h_{{\text{e}}}  {1}.{1})\) ④ Determine the air supply temperature t_{0}: \(t_{0} = t_{{{\text{d}},{1}.{1}}}  \left( {0.{88} + {1}.{22}h_{{\text{e}}} } \right)\Delta t_{{\text{g}}}\) ⑤ Calculate air supply velocity u_{0}: assume diffuser size b, l, preliminary determination of inlet area F, then, \(u_{0} = Q_{{\text{n}}} /[\rho c_{{\text{p}}} (t_{{\text{n}}}  t_{0} )F]\) ⑥ Check the control air velocity at 1.0 m from the vertical wall u_{m,1.0} If u_{m,1.0} ≤ 0.5 (or the specified value), the design requirement can be met. Otherwise, return to step ⑤ to reassume the diffuser size b, l ⑦ Check the air velocity at the end of the jet air reservoir u_{m,x}: If u_{m,x} ≤ 0.3 m/s (or the specified value), the calculation procedure is finished. Otherwise, return to the ⑤ step to reassume b, l. Note l should be appropriate to meet the wall size ⑧ Design parameters, including u_{0}, t_{0}, diffuser size l × b, installation height h, etc. are determined 