Heating with Wood - Frequently Asked Questions
Q: "How can we best burn clean?"
A. How and what you burn determines the economy, environmental consequence and efficiency of your wood burning stove or insert.
Use dry, seasoned and split wood.
Select an EPA-certified wood stove or insert which produce up to 85% less emissions than appliances manufactured before July 1, 1986
Make sure the stove’s installation and flue system is safe and functioning properly with an annual chimney inspection and cleaning if needed and maintain your stove or insert to manufacturer recommendation.
NEVER burn garbage in a wood stove or fireplace.
If you have an old stove, insert or fireplace and cannot afford a newer stove or insert, enhance the capabilities of your current appliance by following the tips in the” Responsible Wood Burning” section below.
Q: "Why should I heat with Wood?"
A. There are many benefits result from the decision to heat with wood:
Wood heat contributes to the conservation of the world’s non-renewable fossil fuels.
Wood heat enhances the nation’s energy independence
In most instances, heating with wood will save you money.
Growing trees clean the air of carbon dioxide having a positive effect on our carbon footprint
However, linked to these benefits is the environmental responsibility to burn clean and as efficiently as possible. This guide will provide information on proper wood burning, with tips to help you burn smart for lower emissions for a cleaner environment.
Q: "How do I figure out how efficient my fuel is?"
Want some information on the amount f heat produced by various fuel types? Click HERE for the Fuel Value Calculator by the Forest Products Laboratory. Calculate Btu's for a wide variety of fuels - everything from wet green to propane.
Q. “How can I tell if a wood stove is a new clean burning, high efficiency model?”
A. Regulations enacted by the U.S. Environmental Protection Agency (EPA) require all wood stoves and fireplace inserts manufactured and sold after July 1, 1992 to pass stringent emission tests. An EPA label identifies as a new clean burning, high efficiency model, and is found on every certified stove and insert.
Q. “How can I tell if a stove or insert is sized right for my home?”
A. Consider your geographic location and climate, the number of rooms you wish to heat, and the construction of your home such as room size, ceiling height, number of windows, and insulation. Most stoves and inserts provide a range of square feet each model is expected to heat. Your local Hearth Specialist will tell you where your situation will fall within that range.
Q. “I already have an older stove. Is there anything I can do to make it burn cleaner?”
A. Yes. Even if you can’t upgrade to a new EPA certified stove or fireplace insert right away, you can still improve the performance of your current stove. Have your wood heating system inspected and cleaned by a certified specialist. Make sure all the gaskets are sound and the door shuts tight for better air control. Read and follow the suggestions for optimal operation of your stove.
Q “Can I install my own stove, or should I have the installation done professionally?”
A. Having the installation done professionally ensures that it will be installed safely and will meet all codes. It’s strongly recommended by the stove, insert and fireplace manufacturers that the installation be done by a professional. A Hearth Specialty Retailer can provide you with professional installation assistance. Installers are certified by HEARTH, a nonprofit foundation that trains installers and fire code inspectors. For owners who choose to do their own installation, follow the manufacturer’s instructions explicitly. To locate a HEARTH certified specialist, go to www.HPBEF.org.
Q. “Why is wood smoke undesirable?”
A. Smoke, in the form of solid particles (or “particulates”) and volatile gases, is unburned fuel. When a stove fails to achieve the high combustion temperatures necessary to burn the particulates and ignite the gases, you have smoke, and a loss of up to half the heating potential of your firewood. A smoking stove is not an efficient heater, and it can also adversely affect air quality. The secondary burn system on EPA certified stoves and inserts, combined with proper burn techniques, can decrease the level of polluting emissions by up to 85%.
Q. “How can I tell if I am operating my wood stove properly?”
A. Check the exhaust coming out of your chimney; the smoke is your operational barometer. If your fire is burning properly, you should see the white transparent steam of evaporating water, some darker and opaque smoke will be slightly visible. The darker the color of the exhaust, the less efficiently you are burning the appliance. It may be necessary to adjust the operation, such as giving the fire more air or using smaller (or drier) wood for a longer time, to decrease the density of the smoke. A 15% opacity, or wispy white smoke, indicates efficient operation. Some states regulate opacity levels from wood stove chimneys.
Q. “Are there times when my wood stove or fireplace insert will emit more smoke?”
A. There are two periods in the operation of a wood stove most vulnerable to creating smoky emissions – during startup and when you refuel. However, these smoky periods can be dramatically minimized by proper operation.
Q. “What can I do to minimize the amount of smoke at startup and refueling?”
A. Create and maintain drafting conditions necessary for clean combustion. A good draft occurs when your chimney consistently draws enough air into the firebox providing adequate oxygen to completely burn the fuel. To create this draft, you must preheat the chimney. The amount of time that will take will vary with the height of the chimney, outside exposure and construction, and barometric conditions. Typically, preheating requires at least 5-15 minutes of a hot and vigorous fire.
When reloading, place small split pieces of wood on the bed of coals and fully open the air supply before adding larger pieces of wood. Using smaller pieces of wood during reloading encourages rapid reheating of the chimney.
You will know the chimney is drafting when each large piece of dry wood you add ignites quickly, without a loss in the intensity of the fire. Listen for the sound of air entering the firebox. A constant movement of air signals that a good draft has been achieved.
Some manufacturers provide specific guidelines involving indirect monitoring of the chimney exhaust temperatures. Typically, chimney connector temperatures must reach 500-600 degrees F. before the chimney is fully primed. Always follow your manufacturer’s instructions when temperature and startup procedures are specified.
Q. “How do I preheat my chimney?”
A. At startup, remove all but a thin layer of ashes from your firebox. Insert five or six crumpled individual pieces of newspaper and dry finely split kindling or a firelighter. Firmly open the air supply (dampers) to the woodstove and ignite the paper on all aides. You may find it necessary to leave the stove door slightly ajar during the first few moments of the fire. After the first load ignites, add more kindling until the chimney is preheated. The fire should burn briskly and full of flame during the startup if you are operating the wood stove properly.
When reloading, place finely split pieces of wood on the charcoal bed and fully open the air supply. Using smaller pieces of wood during reloading encouraged rapid reheating of the chimney.
You’ll know the chimney is preheated when each large piece of wood you add to the fire burns vigorously, without a loss in intensity of the fire. Keep listening to the sound of the air entering the stove. A constant and rising movement of air signals that good drafting conditions have been achieved.
Some wood stove manufacturers provide specific guidelines for startup and preheating phases involving the indirect monitoring of chimney exhaust temperatures. Typically, chimney connector temperatures must reach 500-600 degrees F. before the chimney is fully primed. Follow your manufacturer’s instructions when temperature and startup procedures are specified.
Q. “Once I have preheated my chimney, how should I operate the stove?”
A. Always refer to your wood stove manufacturer’s operation manual and follow the instructions for your particular make and model.
Q. “Do I operate my stove differently in cold vs. warm weather conditions?”
A. Yes. During the warmer seasons of spring and fall, control the total heat output by limiting the amount of fuel (wood) rather than by closing down the air supply. Make shorter, hot fires using more finely split wood. The actual air supply setting will vary according to your stove instruction, but the fuel loading will be consistently smaller. Let the fire burn out rather than smolder at low air supply setting. When your home requires more heat, restart the fire with kindling as always, but add smaller fuel loads. This allows your stove to operate at maximum efficiency and with minimum emissions. Avoid the temptation of building a big fire and then starving it for air.
Q. “Is it important to have my stove and chimney cleaned?”
A. Yes. Smoke rising through your chimney may condense and build up on the cooler inside walls forming a substance known as creosote. The volatile substance can ignite and burn in the chimney. Many chimneys and installations are unable to withstand these dangerous creosote fires; the results can be tragic. Chimneys and vents for wood stoves and inserts also perform the necessary function of directly venting the hot gases from a fire away from the house. If the chimneys or vents are obstructed by debris or animals the hot gases can be forced back into the home. At the same time, wood stoves and inserts require service to ensure they are operating correctly.
Q. “Is it important to have my stove, insert or fireplace and its chimney cleaned?”
A. Yes. Smoke rising through your chimney may condense and build up, forming a substance known as creosote. This volatile substance can ignite and burn in the chimney. The results can be tragic. The Chimney Safety Institute of America recommends that all chimneys be inspected and cleaned annually, or more frequently depending on usage. The stove, insert or fireplace should also be inspected annually and serviced, if needed, to ensure that it is operating correctly.
Q. “Does it matter what kind of wood I use?”
A. When trees are initially cut down, they contain a great deal of moisture. To dry the wood it should be split and stacked loosely in a crosswise pattern to enable good air circulation. Cover the wood pile to protect it from rain, snow and dew, but leave the sides open for air flow. A sunny location is best, keep it off the ground and away from buildings. Softwoods should be allowed to dry in this fashion at least six months. Hardwood takes longer to dry and may take more than a year to be fully cured.
Q. “What is the difference in the types of wood?
A. Softwoods such as fir and cedar, grow fast and burn fast and hot. They are best for starting the fire. Hardwoods are primarily deciduous trees such as oak and maple and they burn longer than softwoods. See a chart of “wood heating values” at www.lrapa.org for more information on which wood is best.
Q. “Is it important to season wood before burning it?”
A. The seasoning, or drying, process allows most of the natural moisture found in wood to evaporate, making it easier to burn. A properly seasoned log will have 20%-30% moisture content. Wood only dries from the surface inward so un-split pieces dry very slowly. To properly season wood, split the logs as soon as possible and stack them in a dry spot for 6-18 months. Pile the wood loosely, allowing air to circulate through the split logs. Hardwoods take longer to dry than softwoods. Humidity and temperature levels also impact drying time.
Q. “What’s the best way to load wood into my stove or insert?”
A. Avoid placing pieces of wood in parallel directions, where they may stack too closely. Vary the position of the wood in the firebox to maximize the exposed surface area of each piece of wood. Only use wood properly sized for your stove’s fire chamber. Complete wood combustion requires wood (fuel), temperature (heat), and oxygen (air) to burn completely and cleanly.
Q. “Is there anything I shouldn’t burn?”
A. Never burn garbage, plastic, foil, or any kind of chemically treated or painted wood. They all produce noxious fumes; these are dangerous and highly polluting. Additionally, if you have a catalytic stove, the residue from burning plastics may clog the catalytic combustor.
Q. "What other questions do you have?"
A. Ask a certified wood hearth specialist. To find a specialist near you, click the Where to Shop button on the left.