Abstract: An air control system (33) for an exhaust system (32) of a commercial or institutional kitchen (12) of a facility (10) in which the volume rate of air exhausted may be increased to improve the comfort, health, and safety conditions in the kitchen (12) and the rest of the facility (10). Comfort, health or safety may be determined by sensing a parameter in the ambient air environment (28), such as temperature and/or gas level. With the exhaust system (32) operating at a first volume rate to handle the activity of the cooking units 18, the air control system (33) causes exhaust system (32) to increase the volume rate toward a second, higher volume rate to exhaust more air from the ambient air environment (28) thereby reducing the temperature or gas level in the facility (10) to improve comfort and reduce load on a HVAC system (30) or to improve air quality which has health and safety benefits as well.