Kitchen and bathroom fans vented to the outside and used regularly will help keep your home healthier and reduce the risk of moisture-related damage to the building.
Kitchen and bathroom exhaust fans
Kitchens and bathrooms produce odors and a lot of moisture that can cause problems if the rooms are not properly ventilated. Excessive moisture resulting from poor ventilation is one of the main causes of mold in homes, and can lead to rot and other damage to the building's structure. Also, gas ovens and gas cooktops produce carbon monoxide, nitrogen dioxide, water vapor and other pollutants that should be vented out of the kitchen.
Venting kitchen range hoods and bathroom fans to the outdoors reduces the amount of moisture inside the home and helps keep the indoor air healthier. Energy Star–qualified exhaust fans have durable, high performance motors and on average, they use 65% less energy than non-Energy Star models.
Energy Star exhaust fans are also less noisy. Energy Star–qualified bathroom fans and range hood fans are required to be quieter (less than 2.0 sones) so that people will be more likely to use them.
More exhaust fan tips
- Don't supersize. Don't buy overpowered range exhaust hoods; they can cause backdrafting of fireplaces and other combustion appliances. Backdrafting can occur when an exhaust fan, clothes dryer or leaky ducts negatively pressurize a house; this negative pressure can pull carbon monoxide into the house from the flue of a fireplace, furnace or water heater. See our know-how feature on Carbon Monoxide and Combustion Safety for information about preventing backdrafting.
- Control fans automatically. CALGreen, California's green building code, requires bathrooms in new homes, additions and renovations to be Energy Star-qualified. They also have to be controlled by a humidity control device to ensure that the fan stays on long enough to adequately ventilate the room. Humidity controllers automatically switch on when moisture in the air reaches a threshold level, and shut down when the moisture level subsides.
- Learn more. The Home Ventilating Institute has detailed information on what to look for when purchasing a bathroom or range hood exhaust fan, including recommended ventilation rates based on bathroom size, kitchen size, oven/range output and location of hood: www.hvi.org/publications/index.cfm.