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Ventilation Design Handbook on Animal Research Facilities Using Static Microisolators 
Laminar flow change station 
5 racks 
Cages : Microisolator (with filter top) mouse cage 
5 mice per cage 
Rack: Static system 
6 shelves per rack 
7 cages per shelf (42 cages per rack) 
Supply: 2 radial supplies each providing 270cfm (0.1 3m Vs) for a total of 15 ACH 
Supply discharge temperature, 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 220 cfm (0. lmVs) 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 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, which was in the center of 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, which were 
validated previously (see 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 the amount 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 dimension 0.61m (24”) x 0.61m 
(24”) x 0.81m (32”) located in one of the comers of the room. 
