Good ventilation prevents moisture and excess build-up of mold and mildew which are not only detrimental to your health, but can also lead to the deterioration of structure supports and walls.
Bathroom ceiling fans; with or without lights, or light, nightlight, and built-in heater combinations, are called intermittent ventilation and are used to capture and remove pollutants quickly at the source. The purpose is to exhaust excessive moisture or pollutants before they can spread to other parts of the house. Areas requiring this type of ventilation are bathrooms, kitchens, utility rooms, exercise rooms, workshops, garages and home offices.
Q. What size fan will I need?
A. For bathrooms up to 100 square feet in area, it is recommended that an exhaust fan provide 1cfm per square foot at approximately eight air changes per hour. And for proper ventilation, the fan should be left on for around 20 minutes after usage; you may want to install an automatic timer. Install a separate fan in steam showers that can be turned on after use. For an 8'x5' room with an 8' ceiling = 40 sq ft, you will need a fan rated at 40cfm. For larger bathrooms install a 150cfm fan so that the air can be pulled through the entire room and exhausted at a central location. Or, you can install multi fans; one over the toilet, in the shower, and over the tub. This second method is very effective and provides ventilation where and when it's needed, but both methods work well.
Examples of Bathroom Fans
Q. Where should I install the fan?
A. Typically the exhaust points should be located over or near the shower or tub and in an enclosed water closet.
Q. If mirrors stay steamed up or the grill is dripping water, is the fan(s) operating correctly?
A. You could try leaving the fan on longer to carry out more moisture, or check the design of the duct work. Poor design or damage may prevent the fan from moving the moisture out. You can insulate the ducts and check the roof jack which may be allowing rain to come into the duct, or it could be that condensation from warm, humid air in the house is striking the cold duct surface.
Q. What is a sone level?
A. Sound levels are measured in sones. The higher the sone level, the noisier the fan. Buy as quiet a fan as you can afford. The way a fan is installed will affect its noise level. A low-sone fan attached to a duct that twists and turns, or is kinked or too small, will be just as noisy as the noisiest model.
Amongst our mix are Whisper ventilation fans. These ceiling fans have design improvements made specifically for low sone - which means less noise, and they're EnergyStar® qualified.