Commercial kitchen exhaust fans which are a vital part of your ventilation system. They help to remove odors and improve indoor air quality. Commercial kitchen fans also remove moisture that can increase the level of humidity. Humidity causes mold, mildew and bacteria growth which can ultimately result in major health code violations. A Heat Recovery Ventilator (HRV) also exhausts moisture and odors. An HRV is a self-contained ventilation system that provides balanced air intake and exhaust.