What is secondary combustion in a wood stove and do secondary burn models actually save money on firewood in Ottawa?

Secondary combustion in a wood stove is a process where the stove re-burns the smoke and gases that would normally escape up the chimney, extracting significantly more heat from the same amount of wood. Modern EPA-certified wood stoves achieve this through secondary air tubes or baffles that introduce preheated air above the primary fire, igniting the volatile gases at temperatures around 1,000 degrees Fahrenheit and creating those mesmerizing dancing flames you see in the upper firebox.

In Ottawa's climate, secondary burn wood stoves absolutely save money on firewood compared to older, non-EPA stoves or open fireplaces. A modern secondary combustion stove operates at 70 to 80 percent efficiency, meaning you extract 70 to 80 percent of the available heat from your wood. Compare this to an older stove at 50 to 60 percent efficiency or an open masonry fireplace at just 30 to 40 percent efficiency, and the savings become substantial. An Ottawa household burning 6 cords of seasoned hardwood per season in an old stove might reduce consumption to 3.5 to 4 cords with a modern secondary burn unit — a savings of $700 to $1,100 annually at current Ottawa firewood prices of $350 to $450 per cord.

The secondary combustion process also burns much cleaner, producing less creosote buildup in your chimney. This matters enormously in Ottawa because our long heating season from October through April means more wood burning and more potential for dangerous creosote accumulation. Less creosote means safer operation and potentially reduced chimney cleaning frequency, though annual cleaning by a WETT-certified sweep remains essential regardless of stove type.

Secondary burn stoves do require proper operation to achieve maximum efficiency. You need well-seasoned hardwood with 15 to 20 percent moisture content — wet or green wood will not burn hot enough to activate secondary combustion effectively. The stove must reach operating temperature before you reduce the air controls, and you need to maintain sufficient heat to keep the secondary burn active. Done correctly, you'll see those characteristic secondary flames dancing above the primary fire, indicating the stove is extracting maximum heat and burning extremely clean.

When shopping for a secondary burn wood stove in Ottawa, expect to invest $2,500 to $5,000 for the stove itself, plus $2,000 to $4,500 for professional installation including chimney pipe, hearth pad, and WETT certification. The fuel savings typically pay for the upgrade within 3 to 5 years compared to an older, inefficient unit. If you're considering upgrading to a modern secondary combustion wood stove, you can browse WETT-certified installers through the Ottawa Construction Network directory to ensure proper installation and insurance compliance.