Fireplace #52: Square Center-Pivot Damper With Chains Hanging Down
These metal clad square center-pivot pull chain dampers are rare. They are mostly found in double-sided fireplaces that face two rooms. These are their characteristics:
They have a square (image 52-1) or short-rectangle (image 52-2) sheet metal damper door.
The door has two chains hanging down. One to open the damper, and one to close it. (image 52-1)
The metal clad firebox walls get slightly narrower as you go up toward the damper. (image 52-1)
In this particular application it is easiest to install a chimney plug device below the damper, since the damper is set so high above the firebox.
Chimella above or below the damper?
52-4: Chimella In Flue Tile
If the wall to wall dimension below the damper is less than 19″x25″ then you can use a Large Chimella below the closed damper. If it is larger than that, then you would open the damper and install the Chimella above the damper. Considering this damper is usually set above the firebox about 24″ vertically. This can be challenging to install a Chimella above the damper.
It is important to open a Chimella properly when installing, so it gets a tight fit. Here is a Video to see how the Chimella works. Pay close attention the the part of the video about tightening the collar with the purple dot on it.
The Chimney Balloon can work well in this application. It generally installs just below the damper (image 52-6). However it is an inflatable, so it is not as durable as the other options. And it requires a top-off on air every 6 to 12 months because of the swings in outside air temperature.
Here are the steps to use a Chimney Balloon:
Measure the size of the opening about 8 vertical inches below the damper. Measure wall to wall left to right and front to back (image 32-3).
From those dimensions order a Custom Chimney Balloon.