Volume I - Section III - Evaluation of Results and Recommendations 
Page HI - 27 
Figure 3.33 Velocity Vectors on the Centerline for the Basecase Showing the Strong Upward 
Flow from the Change Station 
Cases 53 to 61 were run with an alternative change station design that had similar heat 
dissipation but a higher amount of recirculated air. This design seems to produce results very 
similar to those of the original change station. 
It is interesting that two of the best performances for the room breathing zone C0 2 and NH ? 
concentrations come out of this group of tests. Case 12 (slot supply, ceiling exhaust, change 
station off) and case 59 (slot supply, low level exhaust, alternative change station) produce the 
lowest C0 2 and NH 3 concentrations in the room. That there is no obvious link between these 
cases, and since other slot supply cases do not appear to be so good, this information serves to 
confirm that such complex airflows take place in animal rooms, it is difficult to predict how they 
will perform without detailed analysis. 
3.1.4 Pressurization of Room relative to Corridor 
Cases 16 to 18 were run with positive pressurization in the room instead of negative, with 
lOOcfm (4.72e-2 m 3 /s) air leaving rather than entering the room via the door. These cases should 
be compared with cases 1, 4 and 7, which are all cases with ceiling exhausts. Cases 45 to 47 
varied the amount of air flowing in or out (50cfm in, Ocfm, and 50cfm out) of the door cracks 
and should be compared with cases 1 and 16. 
Figures 3.34 to 3.37 show comparisons of C0 2 and NH 3 concentrations for different room 
pressurizations. 
