Proper bathroom ventilation is more than just an issue of fogged mirrors, damp towels and odors. Excessive humidity inside bathrooms triggers mold growth, not only on exposed surfaces but also hidden inside wall voids where damp air infiltrates. Condensation that forms as the room cools after bathing can peel paint or wallpaper and degrade drywall. It also spawns mildew and makes tile floors slippery. Humidity from a damp bathroom easily migrates into other parts of the home as well.
The goal of adequate bathroom ventilation is to exhaust humid indoor air outdoors. Opening a window is one way to do this. However, a powered fan is far more effective and faster. Installed in the bathroom ceiling — or in an exterior wall if the room includes one — a bathroom ventilation fan keeps the bathroom environment drier, healthier, and more pleasant.
Here are some parameters for effective ventilation:
- Adequate capacity. In order to remove water vapor in a short time, the vent fan’s air-moving capacity should match the size of the room. In general, the fan should exhaust 1 cubic-feet-per-minute (CFM) of air per each square foot. This figure assumes a standard bathroom with one sink, toilet, bathtub, and shower.
- Outdoor venting. A bathroom fan should be connected directly to a dedicated duct that exhausts into outdoor air. Never vent a fan into the attic, as moist air will rot attic structure and trigger mold. Wall-mounted fans must also vent through an exterior wall into the outdoors.
- Timer control. Running a fan for an excessively long period can pull cooled or heated air out of the house. A standard vent fan should run for about 15 minutes after bathing or other use to fully exhaust damp air and odors. Wiring the fan to a timer switch automates the process so the bathroom is adequately ventilated.
- Electrical safety. For safety in the wet bathroom conditions, the fan should be connected to a GFCI circuit (Ground Fault Circuit Interrupter).
Ask Paitson Bros., your local source for a healthy, comfortable indoor environment since 1922, for more information about the benefits of installing a bathroom ventilation fan.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922