What is a barometric damper on an oil furnace?

A barometric damper regulates how quickly the draft, or heated air and combustion gases, moves within an oil furnace. A barometric damper is installed between the furnace exhaust pipe and chimney in order to also block backdrafts of outside air into the heating element.

Barometric dampers, which are also called draft regulators, are designed to make oil furnaces more efficient. A draft that is too slow leads to incomplete combustion, increases soot buildup and does not effectively purge carbon monoxide out of the system. A draft that moves too quickly vents more heated air outside instead, allowing for it to transfer into the building. This can also cause hot chimneys, a major fire hazard.