As the old saw goes, wood warms you five times: When you cut it, when you split it, when you stack it, when you haul it and when you burn it. But burning it produces more than warmth. It produces polluting smoke.
Wood smoke is unburned fuel, says Deborah A. Janes of the federal Environmental Protection Agency's research and development staff in Research Triangle Park, N.C. The key to reducing air pollution from wood stoves is to burn the fuel more completely. The new stoves, by law, do just that.
"Cleaner burning wood stoves that employ the latest technology result in less smoke up the chimney because the stove burns much of the smoke as well," says Geoff Wurzel, director of communications at the Wood Heating Alliance in Washington D.C.
In order to recapture the heat energy stored in smoke, some newer stoves use a catalytic converter. This honeycombed device is designed to lower the kindling temperature of smoky gases. These smoky gases contain as much as 50 percent of the available heat in the wood. In other stoves, the heat from these gases is wasted. But the catalytic converter allows the gases to reignite, releasing more heat energy.
Wood stoves today have efficiency ratings set by the EPA that buyers should consider. Old stoves have ratings of 40 to 50 percent. Today's stoves boast efficiencies of 70 to 80 percent.
"This translates directly into more heat per load of wood, saving you money if you buy your firewood or time if you cut your own," says Jack Hughes, president and CEO of Vermont Castings Inc., a Randolph, Vt., producer of wood stoves.
According to Mr. Hughes, a stove with an efficiency rating of 75 percent could give you as much heat from two cords of wood as one with a rating of 50 percent could give you from three cords.
Besides jotting down the efficiency rating as you browse, also look at the material from which the stove is made. This will either be steel or cast iron.
Steel appliances are made by welding together individual sections of plate or rolled steel. The use of this fabricating technique makes the steel stove both easy and economical to manufacture. Steel stoves also tend to look more contemporary, important if you are more fashion-oriented than fuel-oriented.
Cast iron is the more traditional material for stoves. Because of its durability, aesthetic possibilities and heat-retaining capabilities, iron has been used to make stoves for over 100 years.
