Options for venting a bathroom exhaust fan include best to worst.
Bath fan vented to attic.
It eliminates the need for routing ductwork through the house and these fans usually dry the bathroom more quickly.
Bathroom exhaust fans perform an important function by removing excess moisture from your home.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.
In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.
In fact i have seen numerous houses that haven t yet had signs of mold with the bath fan venting incorrectly.
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.
The lowdown on venting your bath fan into an attic is that it can be done but it should terminate on the outside.
The truth about attic bathroom venting.
Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
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.
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.
Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.
Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
Vent your bath and kitchen exhaust fans through the roof through a special roof hood.
A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.
Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.
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.
I would by lying if i told you that it will cause problems it may be totally fine.
Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside.
The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.
Can you vent a bathroom exhaust fan into the soffit vents.
This involves running ductwork from the fan usually though an attic and out through the roof.
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.
But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms.
