Condensation On Attic Fan Damper

If your ducts are properly insulated another potential cause of condensation is lack of use.

Condensation on attic fan damper.

The duct should not be aimed at a roof vent or have any loose. Attic air leak into the fan unit unitself from not being well sealed to the ceiling attic floor exhaust damper not opening properly so humid exhaust air doesn t exhaust and stays in the duct getting cold enough to condense and drip back down. Bath fans have a damper designed to keep the outside air from entering in through the fan but that valve doesn t stop warm air from escaping. The damper will help prevent cold air from dumping back down into the house which may lead to condensation right at the fan itself.

There s a damper on the fan housing too but the outside damper is much more likely to stick. The outside damper is stuck. The attic is now pleasant as well just a few degrees warmer than the house. Just as we were ready to move back in we discovered both bathroom fan exhaust ducts as well as the gas dryer duct all upstairs have been filling with condensation.

It should open only under pressure from the warm air to let it out and remain closed the rest of the time. The duct is not kinked but there is a 1 5 inch gap between. The exhaust vent in the powder room downstairs is fine this is a new thing. Find the vent hood on your roof or exterior wall.

First inspect the damper on the outside. Exhaust fan condensation drip.