Can I Exhaust Bathroom Fan Into Attic

No it s never a good idea to have any exhaust fan in your home dump all that hot moist air in your attic.

Can i exhaust bathroom fan into attic.

But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms. Unfortunately we find far too many bath fans that exhaust the moist air into the attic. In those areas ventilation in bathrooms is required but it can be from a window or fan your choice. Whatever area you block with the exhaust duct is a reduction in the area of the gable vent.

Let me tell you. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans. Never vent the bathroom into the attic. It s all outdoor air anyways right.

A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan. It seems like such an easy solution just leave a bathroom vent hose in an attic. It is against the residential code and will lead to mold growth in the attic. Many assume that the fan vents outside through the roof which is the proper method.

Surprisingly bathroom fans are not required by some building codes. Depending on how the attic ventilation is designed the hot moist air exhausted from the duct could be drawn back into the attic through the gable vent. A single exhaust exits through the. You d often blow air from one bathroom into the other and local building inspectors wouldn t approve it.

Otherwise you re inviting a moisture mold rot insect problem in the building. No you should not vent a bathroom fan directly into an attic. Most homeowners that have a bath fan don t give a thought to where the moist air from the bathroom is exhausted. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.

You should never exhaust the bathroom fan directly into the attic. The roof soffit is also an excellent place to vent the bathroom exhaust. Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. Bathroom exhaust fan venting tips and best practices.

Improperly ending a bathroom vent inside an attic can lead to unintended consequences and builders have stopped this bad practice many years ago. This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. 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.

The exhaust vent must terminate outdoors. Several different ways you can move that hot air to the outside. No you cannot vent your bathroom exhaust fan into the attic. Do not simply terminate a bath vent fan duct in an attic as shown in our photo above nor can you just dump the exhaust vent into a crawl space nor into a closed wall floor or ceiling cavity.