Clark Agnew should be the envy of his neighborhood. He has a tight house, a high-efficiency wood stove with its own fresh-air intake, and access to free firewood. A heat recovery ventilator (HRV) keeps indoor air healthy. What’s not to like?
But, as he writes in a Q&A post at Green Building Advisor, the situation is far from ideal. “I have run the stove about 6 or 7 times since we moved in,” Agnew writes. “Three of those times it has back drafted.”
The stove has been installed in Agnew’s basement. It gets combustion air from a 4-inch-diameter vent to the outside, although the line is not connected directly to the stove. Agnew hasn’t had any problems getting a fire started, and the stove “seems to draft wonderfully.”
Wood Fire Direct Melbourne But periodically the stove back drafts the first time was after about 10 to 20 minutes. I was just sitting there enjoying the heat and flames with my 2-year-old, and all of a sudden the fire goes out and smoke starts billowing out from all corners of the stove,” he writes. Plus, there seemed to be some kind of condensation coming out of the air intake.
On another occasion, the stove ran fine until Agnew’s wife turned on a bathroom fan. Once again, smoke billowed from the stove until the fan was turned off. “Third time, the stove had been running for about 20 to 30 minutes,” Agnew continues. “We were up reading books with my 2-year-old and the smoke alarm started going off. I run downstairs and once again, the fire is out and smoke is billowing out, mostly from the top, next to the air intake lever. I can feel air coming in the fresh air vent 1 foot away. After 30 to 60 seconds of this it just sort of stops and the fire picks up again Heating Consultant Melbourne.”
The dealer where Agnew bought his stove suggests a cold chimney might be to blame, or that the stove is merely burning off new paint. Agnew’s stove troubles are the subject of this Q&A Spotlight. This intermittent problem could be caused by one of several factors, GBA senior editor Martin Holladay points out, including a chimney that does not extend above the ridge of the roof or a restricted or undersized outdoor air duct. Another possibility is that a range hood fan, a bathroom exhaust fan, or a clothes dryer is putting the house under negative pressure, Holladay writes. But Agnew can put some of these theories to rest from the start. The chimney is, in fact, high enough; it extends 2 feet above the ridge. And the Vermont Energy Code Handbook, Agnew adds, specifically allows his below-grade stove installation providing certain conditions are met by Wood heaters Melbourne.