Jason, Most of the diagrams on the Chimney Balloon.us show fireplace dampers with the handle in the middle of the damper door. On my fireplace I have the damper handle way off to the right side (see the two attached pictures with the damper open and damper closed). Does this make a difference? Should I still install a Chimney Balloon above my damper? I measured the area above the damper and it is 11" deep and 30" across - TY
Dear TY, Thank you for the two damper photos. The opening and closing mechanism is unique on this fireplace damper. I have seen this type of damper before, but have never take a photo of it. I can tell by the cobwebs hanging in your open flue (in the open damper photo) that you must not use this fireplace very much.
In this particular application I would recommend that you install the Chimney Balloon above the damper. The handle and other damper hardware are in the way below the damper and it looks like the firebox opens to the hearth almost immediately below the damper so there is not much lintel there.
Since your measurements above the damper are 30"x11" and it looks like the flue stair steps smaller as it goes upward I would go with a 33x12 Chimney Balloon in this fireplace flue. You can always go a little larger (up to 6" or so) in the Chimney Balloon size you purchase, just never buy one smaller than your measurements. - Jason