Cold Air Coming Out Of Bathroom Exhaust Fan

The back draft flapper may be stuck in a shut position.

Cold air coming out of bathroom exhaust fan.

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. The fan pushes the moist air you create from taking a shower outside so you don t rot everything in your bathroom. If this has always been a problem you can a help it some by installing about 4 of flexiable hose and mount it with curves like an inverted j or maybe reconnect origional one b replace it with a better fan and add a hose if the present fan is loud. This is a device to close off the vent for air flow trying to come in from the vent pipe.

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. If this is the case in your bathroom you can get an exhaust fan draft blocker. Caulk around the base of the exhaust fan with acrylic siliconized caulking and replace the insulation around. Yes any time you operate a bathroom exhaust vent fan you are removing stale conditioned air from inside and replacing it with outdoor air.

How to stop cold air from a bathroom vent step 1. I guess they are supposed to have flaps in them too. The purpose of the bathroom exhaust fan is to remove excess moisture and odors from the bathroom. 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.

Sometimes they are built right into fan housing where the vent pipe attaches. It just restricts a large air flow back into the house. This will only allow air to flow out and will restrict cold air from coming in. 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 flapper isn t an air tight seal. Other times the flapper will be part of the roof or wall vent where the vent pipe exhausts to the outside. Some of the fancy fans have lights in them and i am told that the fans vary in quality.