Q We just bought a 30-year-old house that has a wood-burning fireplace with a broken damper. We could get it fixed, but we'd rather insert a wood-burning stove, pellet stove or convert it to gas. Also, the gas furnace is original to the house. Naturally, cost is a factor, but we're concerned about environmental costs, air quality and carbon emissions. What should we do?
A Because the furnace, unlike the fireplace, is a necessity, start with the furnace. The price of natural gas is climbing nearly as fast as that of gasoline. By replacing an inefficient furnace, as yours probably is, you can cut your gas consumption by up to 40 percent and associated electric energy consumption by as much as 60 percent, according to energy specialist Phil Smith with the Minnesota Office of Energy Security.
With natural gas costs rising, it won't take long for the new furnace to pay for itself. At the same time, a very high-efficiency furnace can have a big environmental impact, reducing carbon dioxide emissions by as much as 6,000 pounds per year.
Look for a very high-efficiency furnace with the newer type of blower fan motor that adjusts its rate of operation to optimize performance while reducing power consumption. With that and a variable- or two-stage gas valve, a new furnace would be not only more efficient, but also quieter and able to provide greater comfort.
From the perspective of energy efficiency and environmental concerns, the fireplace is simply an aesthetic choice. Depending on how you use it, energy costs could increase or decrease.
Smith offered some considerations:
• Wood and other biomass fuels are considered carbon-neutral while natural gas is considered a major contributor of carbon dioxide, releasing about 125 pounds of carbon dioxide per 10 therms (a therm equals 100,000 BTUs).
• However, the chemical composition of wood smoke and particulates released by wood burning contributes significantly to air-quality problems in urban and suburban areas.
