These Multi Hinge Dampers are not very common. They are sturdy, but also really over-engineered and not easy to disassemble. Here are the characteristics of this damper:
You swing the center damper handle that hangs down into the firebox from front to back to open and close the damper door.
There are numerous cotter pins operating hinges that actuate the damper.
There is a long rectangular damper frame and matching damper door.
Multi- Hinge dampers actuate almost identically to Vestal Dampers , except they have a more complicated actuator.
Because of the hardware below the damper, there is no way to install any draft stopper below the damper. In this particular application you can see through the damper opening. The flue tile terminates a vertical distant of about 18″ above the damper (image 25-3). This makes for a very short smoke chamber, and easier access to the flue tile. That makes the flue tile an ideal location to plug.
If you use the fireplace regularly, use the Chimella
25-4: Chimella installed in flue
If you use your fireplace regularly, and you are looking for the easiest product to take in and out. The Chimella is the best option. You can install it right into your flue tile.
Here are the Steps:
The Chimella sizes to fit when opened in the flue, so you don’t have to be exact with your measurements. It is better to have a Chimella that is too large, than one that it too small in this application.
If the hole you are putting the Chimella in is less than 16″x16″ in width and length then use the Standard Size Chimella.
If the flue tile is bigger than 16″x16″, but less than 19″x25″, then use the Large Chimella.
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.
If you want to plug it and forget it, use the Flueblocker
You will need to take a quick measurement of the flue tile with a ruler (Image 25-3). Then buy a Flueblocker that size, or a little large for the hole. The Flueblocker is a wool pad with extra hems, so you can trim it to size with sharp scissors.
The handle on the Flueblocker is only 1 foot long, so you may want some 6″ handle extenders for your Flueblocker to make it easier to stuff in the flue tile.
What about the Chimney Balloon?
25-5: Chimney Balloon in Flue Tile
You can use a Chimney Balloon to plug a low flue like this. You would need to get a measurement of the length and width of the flue tile first (image 25-3), so you will know what size Chimney Balloon to use. Flue tiles generally take a 12×12, 15×15 or 18×15. Also purchase a HEK handle extender to give the handle some extra length to reach the flue tile (image 25-5).
The Chimney Balloon will require a top-off of air each 6 to 12 months, and it is not quite as durable as the other two options above. So consider it a “Plan B” for this application.