Stove pipe damper question

The damper allows "make-up" air from the room to go up the chimney. As the fire burns, the heat/smoke go up the chimney. If there is no damper, all of the air goes into the firebox, across the fire, and on it's way. This causes the fire to burn very hot & of short duration. The damper tempers the air going up the chimney with room air, allowing the stove to run cooler and longer, and also with better regulation.

I've run m> I have a woodstove. In the front is a slider plate that I can regulate the

I vote for useless. After the fire is out, the damper can be closed to block warm air from going out the chimney or from cold air coming down it. When the fire is burning, proper control over the inlet will determine how well the stove functions. If the proper amount of air is coming in, the same amount will be leaving.

Before air-tight stoves you used a key in the stove pipe to cut down the draft and slow the fire because even with the stove draft closed enough air came in through the cracks to make the fire burn hot. If you have one of these old stoves you need the key.

New air-tight stoves do not need a flew key control since almost no air enters the stove when the draft control is closed. In this case the stove pipe key is useless, just leave it wide open.