Q: Hi Jason, my fireplace is a sort of rectangular shape (more like a trapezoid) measuring 26 x 14. It goes straight up at those dimensions, then changes to slanted pieces of sheet metal up to the damper that is a circular opening 8″ in diameter. I’ve attached my attempt at a drawing. I’m not really sure what size Chimney Balloon I need. Can you advise, please? – CC
A: Dear CC, The diagram helps quite a bit. Thank you for sending that. In this particular case, I would install the Chimney Balloon just above the damper. A 9×9 Chimney Balloon with an HEK extender attached will give you the length of handle you will need to get it installed in the proper place. I would assume from your circular flue that you have either a butterfly damper (one that picots in the middle) or a drop-down damper (hinged on one side and it drops down like a trap door). The 9×9 and HEK combination will work well with either configuration. – Jason