Q. I read your column and enjoy it very much. I always inform my husband of your advice, which he uses. I now find myself with a problem and hope that you can help us. Last October we had our old siding replaced with vinyl siding. We had our house wr apped with insulation and new siding plus new windows.
We have a fireplace in the family room, which we have converted to a gas burning log fireplace. Last year we didn't seem to notice the wind coming in the fireplace. This winter the wind comes in the fireplace on the top, bottom and both sides, I know it has been pretty windy the past few months but it is so cold in our family room when the fireplace is not in use. I have to build a tent over it to keep the cold air out. We talked to the contractor about the problem and he said it was nothing he did , our house should be better and the draft coming from the fireplace is not something he caused. Any ideas as to what could have caused this? We have lived here for 13 years and the gas logs have been in place for about six years. We have never experie nced the draft that we have now.
A. That's a head scratcher. If it is a masonry fireplace with the standard damper, the gas log installer normally installs a one inch "C" clamp on the leading edge of the damper plate so it will not close all the way. That is to vent out carbon monoxide as the log burns and doesn't allow flue gasses into the house that would also contain moisture that would condense on the windows and cause other mischief. Take a peek and see if that's the case. If so, the cold air could be entering the house by that means. Tell me if that is the case but if not then we will go to plan B.
Q. We never had any problems until we had the house wrapped, resided and new windows installed. The air coming in around the fireplace is unbelievable. So what is plan B? I think we need that.
A. OK, here's the science: when you upgraded the "cladding" of the house, including windows, you made it very air tight and through various means, bath fans, kitchen fans, dryers-- even heating the house itself, the house "depressurizes" relative to the outside air and the house is now drawing air in however it can to equalize the inside and outside air pressures. So we need to somehow equalize the pressures and that is what we need to put our heads to.
The most expensive way is an item known as an "air to air heat exchanger" to bring outside air in, warm it up to interior house temperatures and equalize the air pressure. The cheap way would be to somehow equalize the air by some other mechanism, like o pening a window which might seem counter productive when it so cold outside.
Q. Well, after I read this message I went up to the spare bedroom and opened the window just a very small amount. I know you won't believe this or you may but by the time I returned downstairs the family room was warmer and there was no draft coming in from around the fireplace.
A. Bingo. You knew the problem. Now you know the solution. Think about that air to air heat exchanger. They are more useful than you might imagine. My sense is that as we build our houses tighter and tighter and we find that we are getting sicker and sicker from breathing basically the same air over and over, we’ll slowly come to the realization that such forms of ventilation are not just a good idea but critical to our basic health.