Bathroom Fan Into Attic

The rule of thumb is that you need 1 cfm for every square foot of floor area in your bathroom.

Bathroom fan into attic. See bathroom vent duct termination for details about how to terminate the bath exhaust vent duct. You should never exhaust the bathroom fan directly into the attic. 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. It seems like such an easy solution just leave a bathroom vent hose in an attic. Bath fans are sized according to the volume of air they can move measured in cubic feet per minute or cfm.

The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end. Can i vent a bathroom fan into my attic. 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.

To determine which size fan to buy for your bath multiply the room s square footage by 1 1. Buy the right fan. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.

What this means is that in colder weather the vented air with moisture in the air will mix with the attic air causing. You d often blow air from one bathroom into the other and local building inspectors wouldn t approve it. Example model ventilation codes.

Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo. Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.