Air exchanges and proper ventilation in kennel design
Q. How does one calculate how much air movement is appropriate in a kennel? I'm concerned that several air exchanges per hour would pump large amounts of heat and air conditioning through the wall we so carefully sealed and insulated. A large window unit cools our kennel; should I allow it to vent at all times? Is an interior circulating fan required to move out stale air?
A. Dan Chapel says several standards exist to determine how many air changes are needed per hour, and recommends that you consult a specialist in heating and air conditioning. "A lot of air loss through sealed, insulated walls is a concern. You must balance the need for fresh air with the need for an energy-efficient system," he says.
"The air changes, which pull in air from outside to replace air that's been circulated in the interior of your building, have a definite bearing on your energy cost. But if you don't bring in fresh air from the outside, you'll have such problems as odor, bacteria, and disease transmission. It's a fine line between sending horrendous amounts of money to the electric company and creating a problem inside the kennel.
"Instead of pulling in total outdoor air, you could filter and recirculate the air. Try to shoot for a combination of the two," Chapel says. "I suggest you leave the vent open on your window unit unless it's an incredibly hot day, and use an interior circulating fan. Moving air is better for odor control; it also helps make the area seem cooler, even if it's not."
Wayne Usiak suggests you establish zones "so that the air from the kennel doesn't mix with the air in the rest of the clinic. Extend partitions that surround the wards and runs all the way up to the roof. Any door that leads to another room should have a self-closing device," he says.
Other features Usiak recommends include an exhaust fan and a purge fan. "The exhaust fan maintains the air-pressure difference you'll need to control the zone, so that the air flows into the kennel," he says. "The purge fan will effectively remove any localized odors after a mess has been cleaned up.
"Exhausting all the air from the animal-housing zone is a tremendous energy loss," he adds. "Sometimes it's possible to use an air-to-air heat exchanger to preheat or precool incoming air, thereby conserving some energy. If, however, only one heating and air conditioning unit supplies air to all areas of the hospital, don't recirculate the air--the kennel air would mix with the air from the rest of the hospital.
January 1996 Veterinary Economics