Bathroom Exhaust Fan Blowing Into Attic

The extractor fan exhaust fan removes humidity and moisture from the bathroom.

Bathroom exhaust fan blowing into attic. Never vent the bathroom into the attic. Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. The roof soffit is also an excellent place to vent the bathroom exhaust.

If you have access to the attic the fan can vent either through a gable wall or roof. It is against the residential code and will lead to mold growth in the attic. The fan sucks in air from the bathroom and blows it out of through a vent that is runs behinds above the ceiling. The humid air is sucked back in to the attic.

Bathroom exhaust fans perform an important function by removing excess moisture from your home. It works in the same way that a kitchen exhaust hood does except moisture is being moved instead of smoke. 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 warm air will exhaust out the duct and enter back into the attic through the soffit vent or ridge vent.

The science of creating the right atmosphere in your attic space did not really become a focus of homebuilders until the last 8 10 years. Having the fan exhaust into the soffit doesn t help much as the ventilated soffit is the intake for the ventilated attic system. In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover. 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.

The installation process is similar to the ones already discussed. 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. 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. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.

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 venting tips and best practices. To determine which size fan to buy for your bath multiply the room s square footage by 1 1. A bird s nest in a bathroom vent will greatly reduce or eliminate the effectiveness of a bathroom exhaust fan.

Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.