Share thisWe have a cagewash area with extremely poor exhaust design. The space is, on average, at 95% relative humidity. What are the typical environmental operating parameters of a cagewash area? What are ideal velocities in the duct and what is the ideal slope of said duct?
The HVAC systems serving animal cagewash areas are required to overcome extremely harsh conditions such as radiated equipment heat release, periodic equipment steam release, and animal caging odors. These systems need to be designed to maintain space pressure relationships, reduce odors, capture steam, and maintain reasonable comfort conditions for the cagewash custodians.
For persons working in vivarium cagewash areas, thermal comfort depends on many factors including metabolic rates of occupants, type of clothing, room air temperature, radiant heat from cagewash equipment, air speed, and room humidity. Using the Computer Model Method defined by ASHRAE1, the upper limit for acceptable conditions in a typical animal cagewash area is 80°F dry bulb temperature at 55% relative humidity. We recommend that HVAC systems be designed to maintain animal cagewash areas at or below these thermal comfort threshold conditions. The primary purpose of exhaust systems serving animal cagewash areas is to capture and remove high temperature, vapor-laden air, and discharge it to the exterior of the building. Proper design of these exhaust systems includes selecting appropriate duct materials and managing the condensation that naturally occurs within the ductwork.