For hundreds of years, home wood heating technology changed very little. Then in the 1980s, severe air pollution problems across the country were linked to smoke from wood stoves. Soon, wood stove manufacturers were required to design cleaner stoves.

New wood stove designs focus on achieving higher-efficiency combustion, more complete burning of combustion waste gases, and better heating efficiency. Two different designs-"catalytic" and "noncatalytic" stoves-meet wood stove pollution standards. Catalytic stoves use a ceramic catalyst inside the firebox to assist with the burning of waste gases (smoke). Noncatalytic stoves use a combination of sophisticated baffles and air supply designs to burn the gases. In general, catalytic stoves are a little more efficient initially than noncatalytic stoves, but catalysts deteriorate over time and need to be replaced every two to four years to ensure good performance.

 What Is an EPA-certified Wood Stove?

The U.S. Environmental Protection Agency (EPA) requires manufacturers of wood stoves to produce clean-burning wood stoves. New wood stoves (those built after July 1, 1988) cannot produce smoke-related pollutants beyond certain limits. New wood stoves must be affixed with the following two labels:

• A temporary label with information on the compliance status of the model, the particulate matter emission rate, overall thermal efficiency, heat output range, and possibly the overall efficiency of the model.

• A permanent label with the month and year the wood stove was manufactured, model name or number, and serial number. If the wood stove is equipped with catalytic combustors, the permanent label also should indicate the catalytic combustor's inspection and maintenance needs. If you own a wood stove, do not remove this label. If you are looking to purchase a wood stove, check to make sure this label has not been removed.

 Regulatory Information for Manufacturers and Retailers

EPA prohibits manufacturers and commercial owners to sell, offer to sell, or advertise to sell a non-EPA certified wood stove or a new stove that does not have a permanent label affixed to it as described above or a stove that has not been tested when required. (A commercial owner means any person who owns or controls a wood heater in the course of the manufacture, importation, distribution, or sale of the wood heater.)

EPA's Standards of Performance for New Stationary Sources, New Residential Wood Heaters, Final Rule (pdf 105 kb, 19 pages) provides an overview of the requirements for wood stove manufacturers, retailers, and operators as outlined in the final rule promulgated February 26, 1988.

 Regulatory Information for Consumers/Operators of Wood Stoves

Following are the requirements for owners and operators of wood stoves manufactured after 1988:

• The wood stove must be EPA-certified and affixed with a permanent EPA-approved label.
• The permanent label must not be altered, defaced, or removed.
• Wood stoves must be installed or operated in a manner consistent with the instructions on its permanent label and in the owner's manual.
• Wood stoves that were originally equipped with a catalytic combustor cannot be operated if the catalytic element has been deactivated or removed.
• Wood stoves that have been physically altered to exceed the tolerance limits of its certificate of compliance cannot be operated.

EPA's Standards of Performance for New Stationary Sources, New Residential Wood Heaters, Final Rule (pdf 105 kb, 19 pages) provides an overview of the requirements for wood stove manufacturers, retailers, and operators as outlined in the final rule promulgated February 26, 1988.

 What about Non-Certified Wood Stoves?

EPA's regulations for wood stoves affect those built after July 1, 1988. It is unlawful for retailers and manufacturers to sell, offer to sell, or advertise to sell a non-EPA certified wood stove. Although the federal regulation does not prohibit the individual sale of non-certified wood stoves, many cities have adopted local ordinances prohibiting their sale, installation, and operation. Some cities also have implemented restrictions that prohibit issuing of building permits for the installation of a used non-certified wood stove.

The state of Idaho offers taxpayers who buy new wood stoves, pellet stoves, or natural gas or propane heating units for their residences a tax deduction to replace old, uncertified wood stoves. more

 Benefits of Certified Wood Stoves

• Emit 50% to 60% less pollution.
• Use two-thirds less wood.
• Circulate heat more efficiently, so it stays in your home instead of going out the flue.
• Deposit less creosote buildup in chimneys, meaning less cleaning for you!

 Tips for Buying a Wood Stove

Size

First, select a stove best suited for the space-heating requirements of your home and Idaho's climate. Consider ceiling height, room size, and number of rooms to be heated. Next, consult a specialty retailer for experienced advice. It is better to buy a slightly smaller stove and burn it hotter than to install one that is too big and therefore requires you to choke the air supply to stay comfortable. (Choking the air supply emits more pollution.)

Label

If purchasing a used stove, be sure to buy one with an EPA certification label. All certified stoves must have approval labeling from the EPA. Don't get confused - wood stoves often have several labels. A safety label lists requirements for safe clearances to walls, hearths, and chimneys and is often confused with "certification." A safety label from a safety-listing agency is NOT the same as EPA certification. It is very important to understand the difference when selling or shopping for a wood stove.

Permit

Call your local city or county building department to discuss installation and to obtain a permit.

The state of Idaho offers taxpayers who buy new wood stoves, pellet stoves, or natural gas or propane heating units for their residences a tax deduction to replace old, uncertified wood stoves.

 What conditions must be met to receive a tax deduction?

You can deduct the cost of a new natural gas or propane heating unit, pellet stove, or EPA-certified wood stove if:

• it is in your residence,
• it replaces an old wood stove that does not meet EPA requirements,
• the purchase and replacement occurs within the same year, and
• the old wood stove is dropped off at a DEQ-approved site within 30 days.

 How much is the tax deduction?

 How do I receive and show proof of disposal at a DEQ-approved site?

You receive proof via a receipt when you drop your old wood stove off at a DEQ-approved site. (The fire-brick lining must be removed before drop-off.) Notify the drop-off site attendant that you are participating in the tax-deduction program and ask for a DEQ receipt. Fill out pertinent information and have the attendant sign the completed form. Your copy of the tax receipt should be kept with your tax records. Send the remaining top copy to:

Idaho Department of Environmental Quality

Air Quality Division

Wood Smoke Program

1410 N. Hilton

Boise, ID 83706

 Are fireplaces included?

 Why does DEQ approve drop-off locations?

 Approved wood stove drop-off sites

Wood stove operators can dramatically improve a stove's performance by learning to use the stove properly and burning correct fuels. Below is a brief description of key phases in the combustion process and operator tips to assist in achieving a cleaner and more efficient burn.

 Stages of Burning

Evaporation

Before wood can burn, excess water must first be evaporated. The energy required for evaporation is wasted energy, as it could have been used to heat your home instead. Use dried or "seasoned" wood for a more efficient burn.

Emissions

As heat inside the stove intensifies, waste gases (smoke) are released from the wood. Unburned smoke is emitted into the air as pollution or condensed in the chimney, causing creosote buildup. A good supply of oxygen will help burn up or diminish waste gases; conversely, starving a fire of air results in a cooler fire and more unhealthful emissions.

Charcoal

When most of the tar and gases have burned, a bed of coal (charcoal) remains; this bed of coals boosts the combustion process when burning larger pieces of wood. Your best bet-start with a small fire to develop a bed of hot coals. As the coal bed develops and the stove heats up, slowly add larger and larger pieces of wood, stacking them so that air can circulate freely around them. It takes time to build a good coal bed, but the increased amount of heat makes the extra effort worthwhile.

 Tips for Better Burning

Newly cut logs are 50% water. If you burn logs when they're this wet, a high amount of energy is wasted driving off excess moisture, resulting in very poor combustion, increased pollution, and creosote buildup.

The best fuel is "seasoned" wood, wood that has been split and dried by air for at least six months for softwoods or about one year for hardwoods. Seasoned wood has a moisture content of about 20% or less. It tends to be dark in color, cracked on the ends, and light in weight, and its bark is easily broken or peeled. If seasoned wood is not available, manufactured logs made of compressed sawdust are another option.

Do not burn garbage in your stove. Plastics, rubber, paint, oil, painted briquettes, charcoal, and glossy and colored paper release toxics when burned and can cause serious health problems for you, your family, and your neighbors.

Preparing seasoned wood:

• Split wood to help it dry. Wood will dry more quickly and burn best if cut to about 3 1/2 to 6 inches in diameter.
• Stack wood loosely in alternating layers (crisscross fashion) at least one foot above the ground and away from buildings. A sunny, well-ventilated area is best.
• Cover wood to protect it from the weather. Leave the sides open to breezes.
• Give it time to reach the 20% or less moisture content required for seasoned wood. This process takes about six months for softwoods and one year for hardwoods. Think ahead and buy next winter's wood well in advance.

3.  Consider wood heating values.

Periodic inspection of your stove or fireplace is essential for continued safe and clean burning:

• Clean chimneys every year to remove creosote buildup and identify potential problems. Make sure the chimney cap is free of debris, and stovepipe angles and bolts are not corroded.
• Replace the catalytic combustor and baffles every one to four years depending on use, as they are exposed to very high heat and deteriorate with time.
• Replace gaskets on airtight stove doors every few years. Gaskets and seals control the location and flow of air into the appliance.
• Check seams on stoves sealed with furnace cement. Seams may leak and result in heat loss and reduced efficiency.
• Replace broken or missing firebrick.
• Keep the floor of your stove clean of debris and ash.

Smoke from wood burning is a significant source of air pollution and can have serious health consequences. Common health effects from wood smoke include congestion, headaches, and itchy eyes. Wood smoke consists of small airborne particles that can become lodged in our lungs, making breathing difficult and leading to more serious short-term and chronic health problems for certain sensitive populations, especially those with asthma, respiratory or heart conditions, or other illnesses. Children and the elderly are also at risk.

 PM10

 Pollutant Gases

Smoke also contains harmful gases which can adversely human health. Carbon monoxide (CO), for example, reduces the blood's ability to supply oxygen to body tissues. Even small amounts can stress your heart and reduce your ability to exercise.  Oxides of nitrogen (NOx), another gas found in smoke, may lower a child's resistance to lung infections, while hydrocarbons (HC) can injure the lungs and make breathing difficult.

A burn ban is a voluntary or mandatory order issued by DEQ that restricts outdoor burning and the use of wood stoves when an area's air quality is degraded and human health may be adversely impacted. DEQ holds statewide authority to issue burn bans under the Air Pollution Emergency Rule, while local agencies, such as cities and counties, can issue burn bans based on the Air Quality Index. Click here for more information on burn bans.

DEQ acknowledges the Oregon Department of Environmental Quality for wood stove information.