An exterior exhaust vent circulates air, moisture, grease, steam and smoke to an outdoor area of a home or business. Exterior vents are often attached to major appliances, such as a downdraft oven, dryer, furnace, water heater, bathroom or kitchen exhaust fan, and stovetop range hoods.
Exterior exhaust vents help improve the air quality within a home or business by rerouting pollutants, allergens, smoke, steam and moisture into the environment instead of rerouting the polluted air back into the residence or office. Most exhaust systems in kitchens and baths have an exterior exhaust vent, also known as a roof cap, to remove air into the outdoors. Without exterior exhaust vents or roof caps, moisture and condensation may be redistributed into the attic of the building or home, thus increasing the risk of mold developing.