Best Way To Vent Bathroom Fan In Attic

This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.

Best way to vent bathroom fan in 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. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Options for venting a bathroom exhaust fan include best to worst. The correct way to vent a bathroom fan through an attic is to terminate the vent either to the roof or to the gable wall.

Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. This involves running ductwork from the fan usually though an attic and out through the roof. Perhaps some confusion about up or down venting also arises because it is good practice for an overhead fan duct to slope down 1 8 to 1 4 per foot so that any condensation in the fan drips out of the wall vent or soffit vent rather than back into the bath ceiling. To be properly terminated bathroom fans should exit the home through stem vents that are specifically used for this purpose.

Through the roof or an exterior gable wall. If you vent through a soffit where attic vents are often located the moisture will get sucked back up into the attic or roof venting. In order to accomplish this the roof has to have a hole cut in it. 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.

Vent your bath and kitchen exhaust fans through the roof through a special roof hood. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms. If you vent through the roof condensation will drip back into the interior.

Either way the vent will have to go directly to the outside and installed with a vent hood cover.