Cold Air Coming Out Of Bathroom Exhaust Fan

This will only allow air to flow out and will restrict cold air from coming in.

Cold air coming out of bathroom exhaust fan.

The back draft flapper may be stuck in a shut position. The flaps stop the cold outside air from leaking directly into your bathroom and house. It just restricts a large air flow back into the house. This is a device to close off the vent for air flow trying to come in from the vent pipe.

Caulk around the base of the exhaust fan with acrylic siliconized caulking and replace the insulation around. The flapper isn t an air tight seal. Some of the fancy fans have lights in them and i am told that the fans vary in quality. If this is the case in your bathroom you can get an exhaust fan draft blocker.

Other times the flapper will be part of the roof or wall vent where the vent pipe exhausts to the outside. Sometimes they are built right into fan housing where the vent pipe attaches. Maybe the flapper is binding and held open or maybe you have a really strong exhaust somewhere else in the house that sucks air in through the bath fan. While the energy in the air that is exhaust air is lost it is critical to continue to operate bath fans to remove excess moisture odors.

How to stop cold air from a bathroom vent step 1. The fan pushes the moist air you create from taking a shower outside so you don t rot everything in your bathroom. This simple device can be purchased at any hardware store and will keep all unwanted cold drafts out of your bathroom. Clear any insulation away from the unit and use metal tape to cover areas where air may enter the bathroom.

Heat recovery is not a function of the bath fan. The fan itself should have an internal flapper damper that is supposed to block cold air but these dampers usually fit poorly inside the fan housing and air can seep by them. Yes any time you operate a bathroom exhaust vent fan you are removing stale conditioned air from inside and replacing it with outdoor air. If you want to stop cold air you need to have a great damper or double damper at the exhaust hood where the air leaves your home.