Volume II - Section I - Introduction 
Paee II - 3 
Supply. 2 radial supplies each providing 270cfm (0. 13m^/s) for a total of 15 ACH 
Supply discharge temperature of 18.8 °C (66 °F), set such that the exhaust air 
temperature was 22.2 °C (72.0 °F) 
61 percent relative humidity (to provide 50 percent RH at 22.2 °C (72.0 °F) 
Exhausts’. 2 ceiling level exhausts removing 220cfm (0.1 mVs) each 
Makeup Air. lOOcfm (0.047m /s) coming from around the door 
Overall Geometry 
In the majority of the cases considered, the animal room occupied a floor area of 6.10m (20’ 0”) 
X 3.66m (12’ 0”). In some cases that were considered, the width of the room was increased from 
3.66m to 4.22m (14’ 0”). The ceiling height in all cases was 2.74m (9’ 0”). There was only one 
door in the room, mounted centrally on one of the short walls. 
In all the displacement ventilation systems considered in this project, air was introduced through 
ceiling mounted diffusers. All devices were mounted flush with the ceiling surface; there was no 
ductwork present within the upper room volume. The various diffuser types considered in this 
project were all modeled using a combination of several boundary conditions that were validated 
previously (see volume I, section 4.2.2). All the air exited through general exhausts. The number 
and locations of the exhausts were varied. In line with common practice, there was an imbalance 
between the amount of air supplied to the room and exhausted from the room. This leads to an 
overall pressurization of the room relative to the rooms or corridors surrounding the room. The 
relative level of pressurization was a parameter considered in this study. The makeup air to 
compensate for the supply/exhaust imbalance was allowed to enter or leave the room through 
6.35e-3m (0.25”) gaps on three sides of the door. 
The rooms considered in this project all contained five animal cage racks. The rooms also 
contained one of two alternative design change stations. A fuller description of these items is 
given below. The only other item within the room was a sink of 0.61m (24”) x 0.61m (24”) x 
0.81m (32”) that was situated in one of the comers to the room. 
In all cases, the room was considered under dark period conditions, i.e., the lights were off and 
produced no additional heat load to the room. Dark period conditions were chosen because early 
experimental work had indicated that heat, CO2, and NH3 generation were higher in the dark 
period compared with periods in which the lights were on. 
Rack Model 
The overall dimensions of the rack were 1.52m (60”) x 0.61m (24”) x 1.83m (72”) high, as 
shown in figure 1.02. There were six shelves in the rack. The spacing of the shelves was 0.32m 
(12.75”) from top surface to top surface, with the lowest shelf at a height of 0.21m (8.25”) above 
the floor. The shelves were modeled as thin rectangular blocks. Details, such as the connecting 
ties between the shelves and the rollers on which the racks move, were not modeled because 
their effect on the overall flow field and gas concentration distributions was considered 
insignificant. 
