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Ventijation Design Handbook on Animal Research Facilities Using Static Microisolators 
Cases 100 and 101 do not produce the same level of improvement as the original cases 3 and 66, 
which already have very low humidity values (below the 61 percent minimum from the 
experimental data), and so the reduction in humidity does not produce a lower NH3 generation 
rate. 
To further investigate the effect of increasing supply temperature (without re-running all 101 
cases) the data was “post-processed” by adding 3.2 °C (5.8 °F) to the mean temperature for each 
cage. This is equivalent to raising the supply temperature by approximately 4.0 °C (7.2 °F). 
Figures 3.60 and 3.61 show the resulting bar charts for the day 4 cage and room NH3 
concentrations together with the original data. These charts clearly show the reduction in NH3 
concentrations that can be expected when an increased supply temperature is used. A few of the 
cases do not show significant improvements. These are cases where the original run is already at 
the minimum RH (61 percent) used in the generation rate calculation. 
Figure 3.60 Comparison of Cage Day 4 NH 3 Concentrations 
