Exhaust Fan Into Roof Space

Once inside the air heats up and rises higher ultimately exiting through venting at the roof s gables through ridge vents cut into the roof s apex or other vent holes in the roof.

Exhaust fan into roof space.

Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Having a new house built and have found that the bathroom exhaust fans vent into the ceiling space. As the air leaves it creates negative pressure behind it sucking in cool air from below into the soffits and creating a self repeating ventilation process. 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 involves running ductwork from the fan usually though an attic and out through the roof. Also some readers have worried that discharging a bath exhaust vent down through a soffit will permit moisture to rise back up into the attic or roof space if the soffit and roof cavity are vented. It can cause you a lot of problems with mold and mildew forming on the underside of your rafters and decking as well as getting into your insulation. It is because of this that many builders tend to advise against this method.

Hot air exhaust vents located at the peak of the roof allow hot air to escape. Same thing with kitchen rangehoods. No you cannot vent the bathroom exhaust fan into the soffit vents. Several different ways you can move that hot air to the outside.

No it s never a good idea to have any exhaust fan in your home dump all that hot moist air in your attic. Looking forward to moving out of a rental that has the kitchen rangehood vented into the wall cavity. Dumping bathroom exhaust into an attic or under roof space invites costly mold contamination frost under the roof in freezing climates moisture damage to roof sheathing possibly even plywood delamination or rot roof failures and shorter roof shingle life. Certainly it is improper to terminate any exhaust vent directly into an attic or roof space.

Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.