4802 - Control of Ammonia Production in Animal Research Facilities Through Ventilation System Design PDF

This paper considers the effect of air properties on ammonia levels in the cages and main room space of an animal research facility containing mouse static micro-isolators. The ammonia production from mice is affected by the level of relative humidity (RH) of the air, with higher production rates at elevated RH values. The manipulation of the room supply discharge air, therefore, offers a means of reducing ammonia levels in both the cage and room. This paper outlines a study in which the air properties are considered with regard to ammonia production both experimentally and numerically, in the latter case using the technique of airflow modeling. The paper demonstrates that even relatively modest increases in supply temperature can have major implications with regards to ammonia production, leading to the possibility that it may be possible to increase the time between cage bedding changes.