Bathroom Exhaust Fan Blowing Into Attic

The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end.

Bathroom exhaust fan blowing into attic.

Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating. The warm air will exhaust out the duct and enter back into the attic through the soffit vent or ridge vent. In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons.

A bird s nest in a bathroom vent will greatly reduce or eliminate the effectiveness of a bathroom exhaust fan. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. If your attic has been done properly the exhaust from your bathroom is directed through an insulated vent line directly out through a dedicated vent on your roof. The installation process is similar to the ones already discussed.

This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space. Avoid venting through a soffit vent or ridge vent. The humid air is sucked back in to the attic. The extractor fan exhaust fan removes humidity and moisture from the bathroom.

It is against the residential code and will lead to mold growth in the attic. Letting the fan exhaust into an open attic will cause moisture buildup on the underside of the roof. Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out. 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.

The roof soffit is also an excellent place to vent the bathroom exhaust. As for the humidity outside being greater that is the reason for installing fresh air ventilation directly into the return side of the ac bringing in clean. If you have access to the attic the fan can vent either through a gable wall or roof. Bathroom exhaust fan venting tips and best practices.

Never vent the bathroom into the attic. To determine which size fan to buy for your bath multiply the room s square footage by 1 1. It works in the same way that a kitchen exhaust hood does except moisture is being moved instead of smoke. The fan sucks in air from the bathroom and blows it out of through a vent that is runs behinds above the ceiling.

It s also important to note that if you install a roof vent cover for a clothes dryer you must remove the metal screen because it will catch lint and may turn into a fire hazard.