Bathroom Exhaust Fan Into Attic

You d often blow air from one bathroom into the other and local building inspectors wouldn t approve it.

Bathroom exhaust fan into attic.

Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating. No you cannot vent the bathroom exhaust fan into the soffit vents. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans. In order to accomplish this the roof has to have a hole cut in it.

When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form. This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo. The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end. If you vent the bathroom exhaust fan to close to the soffit vents which are vented plates under your homes outer edge and roof your home the air can be sucked right back into the attic from the soffit.

But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms. It is because of this that many builders tend to advise against this method. To determine which size fan to buy for your bath multiply the room s square footage by 1 1. It s also important to note that if you install a roof vent cover for a clothes dryer you must remove the metal screen because it will catch lint and may turn into a fire hazard.

This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space. Surprisingly bathroom fans are not required by some building codes. Can you vent a bathroom exhaust fan into the soffit vents. A bird s nest in a bathroom vent will greatly reduce or eliminate the effectiveness of a bathroom exhaust fan.

Bathroom exhaust fans perform an important function by removing excess moisture from your home. In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside.

Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons.