MEASUREMENT OF VENTILATION RATES USING A TRACER GAS

Use of a tracer gas to measure ventilation rates in animal housing was evaluated utilizing three methods. The gas used was sulfur hexafluoride which was detected by an electron-capture chromatograph. The three tracer methods involved whole-room constant-flow, whole-room decay, and fan-duct constant-flow techniques. Ventilation rates measured ranged from 70 l/sec to 1250 l/sec. When care was exercised in calibration of the detector and in the metering of tracer gas, results were obtained that were within 5% of hot-wire anemometer measurements. All methods depend on complete mixing of tracer gas with the air in the ventilated volume under consideration.