The Auxiliary- Air Fume Hood reduces the loss of expensive tempered air from the laboratory. Ideal for laboratories with inadequate make-up air supply. Auxiliary-Air fume hoods reduce the amount of expensive air-conditoned or heated air that is exhausted to the outside. Between 50% to 70% of the exhaust can be supplied from outside the lab. When there is a shortage of air in the lab, it is less costly to provide an Auxiliary Air fume hood system than to change or enlarge the whole building air handling system. The make up air can be efficiently brought directly to the point of use fume hood.