Fireplace Damper

A fireplace damper is a movable plate or valve mechanism located in the throat or top of the chimney that controls airflow between the firebox and the flue. When open, the damper allows smoke and combustion gases to rise up the chimney and exit the building. When closed, it seals the flue to prevent conditioned indoor air from escaping up the chimney and blocks cold outside air and downdrafts from entering the home. Proper damper operation is essential for both fireplace performance and home energy efficiency. Traditional throat dampers are located just above the firebox and are operated by a handle or rotary control accessible from inside the fireplace. Top-mounted dampers, installed at the chimney crown, offer superior sealing performance and are often used as replacements when throat dampers deteriorate. A well-functioning damper can significantly reduce heating and cooling costs by preventing the chimney from acting as an open air duct when the fireplace is not in use. Annual inspection of damper condition and operation should be part of every chimney maintenance routine.