In Attic Bathroom Exhaust Fan

Section 1203 4 2 1 of california s building code requires all bathrooms with a bathtub shower spa or similar fixtures to be ventilated by an exhaust fan.

In attic bathroom exhaust fan.

2 moisture droplets dripping from the exhaust fan or ducting. Each bathroom has its own exhaust fan. Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof. Condensate may also be dripping off the exterior surface of the vent duct in attic or crawl space.

It seems like such an easy solution just leave a bathroom vent hose in an attic. No you should not vent a bathroom fan directly into an attic. It s all outdoor air anyways right. The fan is able to accommodate anywhere from 1 200 to 1 800 square feet of attic space.

You ve now put the water right back up into the attic without realizing it. It s perfect for reducing cooling costs as it pulls fresh air from outside and expels warm attic air out through the exhaust vents. Just a year ago i saw the absolute best bath exhaust fan roof cap. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end.

No you cannot vent your bathroom exhaust fan into the attic. You ve now put the water right back up into the attic without realizing it. Bath exhaust is almost always warm and this air will float up and into the soffit ventilation openings. As warm moist air moves through a fans vent system in the attic the duct often become cooler especially in the winter thus condensate may form and drip back down through the fan itself.

Surprisingly bathroom fans are not required by some building codes. Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. Most roof overhangs today have continuous soffit ventilation strips. In those areas ventilation in bathrooms is required but it can be from a window or fan your choice.

One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms. No it s never a good idea to have any exhaust fan in your home dump all that hot moist air in your attic. Each fan vents separately out the roof. It can cause you a lot of problems with mold and mildew forming on the underside of your rafters and decking as well as getting into your insulation.

Air vent 18 inch dia electric gable vent fan courtesy of home depot. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.