Q: Jason I have a 7 unit apartment building that has a very unusual setup for the fireplaces in each of the flats. In order for the fireplaces to draw well enough to use the fireplaces, I had to put an exhaust fan on the top of the chimney. Unfortunately, this makes all of the dampers whistle all the time because the dampers are not tight enough and the air is being drawn through them. Will a Chimney Balloon stop the whistle of the air through the damper? The diameters of the flues are 6″-8″ round stainless flue liners – EC
A: Dear EC, The Chimney Balloon will stop the air flow through the chimney but the stainless liners are a pretty slick surface for the Chimney Balloon to grab hold of considering there is an exhaust fan trying to suck it upwards. My suggestion is to use a 9×9 Chimney Balloon for each of the flues. When you install the Chimney Balloon take some string and tie the handle valve portion of the Chimney Balloon to something in the fireplace that is ridged and not going anywhere like the damper hardware. Leave some slack on the string. If the Chimney Balloon begins to be sucked upward by the fan this string tether will keep it from going too far. Also, if you leave slack on the string tether and the slack stays as it was when you installed it then you know the string is an un-needed precaution. The Exhausto fan can suck a lot of air volume through those small 6″ and 8″ flues, and I don’t want to see it suck your Chimney Balloon up into chimney oblivion.