Home Energy — September October 2014
Don Fugler


Bill, the modifications you made to your house seem worthwhile except for the passive air supply near your woodstove (“My Home Energy Audit,” May/June '14, online only). Given the size and relative leakiness of your house, you should not need an additional opening in the envelope to supply air for the woodstove. When the stove door is closed, the chimney flow is likely to equal that of a small bathroom fan, and you do not open an air supply every time you turn on a bathroom fan or use the clothes dryer. That air supply is also next to useless for reducing the possibility of smoke spillage, according to research we did many years ago. You buttoned up the house for better energy performance; just close that air supply as well.

Author Bill Spohn replies:

Don, thanks for the feedback! The main reason for the passive air supply (in my mind) was for comfort. That is, to have the woodstove source combustion air very locally, rather than draw cold outdoor air from the other leaky parts of the house (such as the front door), creating uncomfortable drafts. Even before air sealing, the drafts were present, and I had a hunch it would only get worse. Unscientific testing (the stocking feet test) says it worked!