Volume I - Section II - Animal Room Variations 
Page II - 9 
• The sink in the animal room was modeled as a single rectangular block. The recess formed by 
the shape of the sink was not modeled because the effect of the recess would be negligible on 
the overall flow field within the room. 
• No lighting was assumed in the animal room simulations. The reason for this was that higher 
CO 2 and NH 3 emissions occur during dark (scotophase) conditions (see figure 2.02, section 
4. 1.2.8. 1 and appendix I: sections 3.4. 1.9 and 3.4.1.10). 
• The animal room was intended to be kept at a nominal 22.2 °C (72.0 °F). For the simulations 
the temperature control was assumed to be placed in the exhausts, i.e., the exhaust air 
temperature was set to be 22.2 °C (72.0 °F), and the supply temperatures were set 
appropriately. 
• No leakage occurred into or out of the animal room other than that specified though the 
cracks around the door. 
• Air density variations due to temperature were negligible. Density variation was therefore 
ignored in all terms apart from in the momentum term for the vertical velocity component. 
This is known as the Boussinesq approximation. 
• The levels of CO 2 and NH 3 were so diluted in the whole room simulations, even at their 
source, that the variation of the mixture density due to differing molecular weights was 
negligible. 
2.2 Whole Room Configurations 
To investigate a range of parameters, the basic model described in section 2.1 was modified. 
Wherever possible, only one parameter was varied at a time to fully assess the effect. 
The list of room runs as they were considered is given in table 2.01. Parameters considered in 
this report are: 
• Supply Diffuser Type: Three different diffuser types were considered in this project: radial 
diffusers; low induction diffusers; and slot diffusers. While all these diffuser types are ceiling 
mounted diffusers, the flow patterns resulting from them are fundamentally different (see 
section 4.2.2). See figures 2.06 to 2.08. 
