How To Vent Bathroom Exhaust Fan In Attic

The correct way to vent a bathroom fan through an attic is to terminate the vent either to the roof or to the gable wall.

How to vent bathroom exhaust fan in attic.

Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. You mount a switch in each bathroom. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Options for venting a bathroom exhaust fan include best to worst.

Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. In order to accomplish this the roof has to have a hole cut in it. A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan. This is much easier to do if you have attic access because if you don t you usually have to remove some ceiling drywall and run the ducts along a joist.

This involves running ductwork from the fan usually though an attic and out through the roof. This system is quiet too. Duct already wrapped in insulation at home centers. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof.

In general you can try venting a bath vent fan down but the combination of down direction elbows and total run length may mean that it s ineffective. 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 building code requires a bathroom exhaust fan to vent outside the building so installation of a new bathroom fan necessarily involves installation of ductwork. Because the fan is in the attic you ll hardly hear it.

A single exhaust exits through the roof figure a. You should never exhaust the bathroom fan directly into the attic. Through the roof or an exterior gable wall. Take a look at the installation manual for your fan brand and model.

Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. The manufacturer will give guidance on the total duct length permitted. You can find 4 in. Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems.

Look for the special fans starting at 160 at heating cooling equipment dealers.