When the damper fell out of postion in our 80-year-old home's fireplace, we thought it was as simple a fix as putting it back into place. A visit from a chimney sweep later, we've learned that the damper is rusted out from years and years without a cap on the chimney. So, it seems we need a damper and a chimney cap. And there's something out there that does the job of both that we're considering installing:
It's called a chimney damper. Installed on top of the flue, it's like a trap door with a cord that's dropped down through the chimney. When you want to have a fire in the fireplace, you pull on the cord and to open the damper that's way up on top of your house. Release the cord and that same damper closes.
Chimney dampers close much more tightly than your typical firebox-located damper, meaning the warm air put out by your furnace when the fireplace is not in use has a much more difficult time escaping up and out of the chimney. And when the damper is open, there is absolutely no obstruction overhead (as many chimney caps are) to slow the draw of smoke up and out of the chimney.
The chimney damper's main drawback we've heard about is the fact that they can sometimes freeze shut in snowy, icy weather conditions (exactly the sort of weather where you might want to light a fire in the fireplace).
Has anyone heard of a chimney damper, used one, or considered using one?