How To Vent A Bathroom Fan In The Attic

Options for venting a bathroom exhaust fan include best to worst.

How to vent a bathroom fan in the attic.

Can you vent a bathroom exhaust fan into the soffit vents. No you cannot vent the bathroom exhaust fan into the soffit vents. The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end. The lowdown on venting your bath fan into an attic is that it can be done but it should terminate on the outside.

I would by lying if i told you that it will cause problems it may be totally fine. This involves running ductwork from the fan usually though an attic and out through the roof. 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. This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.

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. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Vent your bath and kitchen exhaust fans through the roof through a special roof hood. The bathroom exhaust ventilation fan disperses air through an opening in the fan housing which is usually 3 inches in diameter and ideally faces in the direction of the ventilation system outlet.

Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. In fact i have seen numerous houses that haven t yet had signs of mold with the bath fan venting incorrectly. But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms. A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.

Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating. A 3 or 4 inch duct connects to the outlet on the fan housing and runs to a side wall or to the roof and connects to a vent cap that allows the. Bathroom exhaust fans perform an important function by removing excess moisture from your home. The truth about attic bathroom venting.

If you vent through the roof condensation will drip back into the interior. To determine which size fan to buy for your bath multiply the room s square footage by 1 1. I recommend that my clients vent their bath fans out a gable wall if at all possible when not using an hrv or erv that is.