Go Green by Heating with Wood

By Marge Padgitt

There is nothing like the warmth and coziness of a hearth fire for a comfortable evening at home. But with the increased prices of gas, many people think “energy efficient” first, and “ambience” last, and have turned to alternatives for heating their homes.

When the energy crisis hit the U.S. hard in the 1970’s, manufacturing companies answered the call for wood-burning stoves with large, heavy, and inefficient appliances. Today’s options are varied and high-tech. Manufacturers have now had over 30 years to perfect their art; new appliances are much improved over their predecessor’s, offering high-efficiency and low emissions, and appliances that use much less wood to provide the same amount of heat. Using the renewable resource of wood makes modern wood-burning appliances very Green and earth-friendly. Homeowners now have a large selection in heating options. I hope these suggestions will be helpful to you in making a decision about which type of wood-burning appliance to purchase.

The Rumford Fireplace– Designed by Count Rumford in the 1700’s, this design has not been improved on to this day. The shallow depth, curved throat, angled side walls, and higher opening, combined with a smaller flue provide much more heat than the standard “box style” fireplace. Compared to a standard fireplace, which produces –30% to +5% in efficiency (meaning most of the heat goes up the chimney), the +40% efficiency Rumford far surpasses its competitor. Recent testing shows that properly designed Rumford fireplaces, throats, and flues are very clean burning and produce low emissions. Don’t expect to heat the entire house, but a Rumford will definitely heat the room it is in and maybe more space depending on the square footage in the area.

Historic homes are perfect for utilizing the Rumford design, which looks authentic and ads ambience to the residence, but a Rumford looks great in modern homes, too.

A new method of “Rumfordizing” existing fireplaces has been developed, where a box-style fireplace is transformed into a Rumford style to gain more heat. Some masons and CSIA Certified Chimney Sweeps are employing this method. Not all masons are trained properly in this method of fireplace building, so find a qualified Rumford builder at www.rumford.com, www.csia.org, or www.midwestcsc.org. Cost range- $4,500—$8,000.

Wood-burning Stoves- Gone are the days of the catalytic combustor, since the new EPA approved “non-catalytic” appliances are extremely low in emissions. Today’s wood stoves require less wood to heat the same amount of space, and that translates into savings in the cost of wood, and in your time to load the stove. Where loading was once required every 2 –3 hours, it is now only needed every 4-10 hours. The addition of an electric built-in blower will push the warmed air through the house, but is not necessary for the stove to work.

A wood-burning stove can be installed almost anywhere, provided there is an existing chimney that can be used or an outside wall where a Class A chimney can be installed. Existing chimneys must be brought up to current standards, and this means the installation of a 6” - 8” insulated stainless steel chimney liner. The flue can only be used for the stove—no other appliances can be attached to the same flue.

Wood stoves come in a variety of styles including standard matte black or a beautiful porcelain enamel finish, and are constructed of heavy steel, cast iron, or soapstone. All stoves require a non-combustible floor and wall behind the stove, with clearance to combustibles being different with each manufacturer. The old 36” rule no longer applies with the newer models, so more usable space is available in the room. The EPA regulates woodburning stoves so be sure to get one that is EPA approved and do not use an older model. 55,000—80,000 BTU output. Cost range—$3,000—$4,500

Wood-burning Fireplace Inserts- Sister to the wood-burning stove, this appliance is inserted into an existing masonry fireplace. A correctly sized stainless steel flue liner is necessary, with a connection to the wood stove. Most flues will measure 6” - 8” in diameter—some are in an oval shape. Do not install an insert with out the required steel flue liner with ceramic wool insulation—and have a professional do the installation. If used without a steel liner, the existing flue that was sized originally for your fireplace will be too large for the new appliance to draft correctly and creosote will accumulate on the flue walls. Usually glazed or tar creosote is the type that occurs in this situation, and since it is highly flammable, it is the cause of many chimney fires.

A wood stove insert will produce enough heat to warm a large area (800—3,000 sq. ft.) , and is extremely efficient—usually in the 70% + range for efficiency ratings. Most inserts are EPA approved non-catalytic, which means that a catalytic combustor, which requires maintenance, is not necessary. The addition of an electric built-in blower will push the warmed air through the house. Burn well-seasoned hard woods and you’ll be happy with not only the heat your insert produces, but the fewer times you need to load wood. The EPA regulates fireplace inserts so be sure to get one that is EPA approved and do not use an older model. 60,000—85,000 BTU output. Cost range $3,500—$5,000.

Wood-burning Furnace/boiler - Similar to the woodburning stove, but larger and produce 80,000—300,000 BTU’s or more. Many woodburning furnaces may be installed alongside an existing gas furnace (provided a separate flue is available), or outside the home in a shed, or stand alone outside. Most furnaces have electric fans and use ductwork to distribute the heat throughout the home, boilers use the hydronic underfloor method to distribute heat.

Either a Class A stainless steel chimney is required; or if using an existing masonry chimney, an approved stainless steel flue liner is necessary. Do not use used with a tile flue liner in a masonry chimney due to danger of excessive creosote accumulation and risk of chimney fire. It is extremely important to have a professional CSIA Certified Chimney Sweep or approved manufacturer installer do the analysis of the installation area and the actual installation of the furnace and flue. This is not a do-it-yourselfer project, as there are many critical items that must be taken into consideration including size of flue, location of the furnace, distance of the connecting pipe run, type of materials used, clearances to combustibles, etc. Find an installer at www.csia.org, or ask the manufacturer for help in finding a qualified dealer. Do your homework when selecting a furnace or boiler as there are large differences in efficiency. The EPA currently has no restrictions on woodburning furnaces in most states (except California, Washington, Oregon, and Colorado). Currently, there are no 80,000—250,000 BTU output. Cost range -$5,000 - $7,000.

Masonry Heaters– Arguably the best value in heating alternatives, masonry heaters are old world technology at its best. Designed with a site-built or pre-cast heater core inside of a brick, stone, tile, stucco, or soapstone exterior, and built on site. The masonry mass will be at least 1,760 lbs. The heater has tight fitting doors that are closed during the burn cycle. It has an interior construction consisting of a firebox and heat exchange channels built from refractory components. A masonry heater has the ability to store a very large amount of heat, which means that you can rapidly burn a large amount of wood without overheating the house. The heat is stored in the masonry thermal mass, and then slowly radiates for the next 18 to 24 hours. Loading of wood is only required approximately once every 12 hours. The heater burns the wood quickly and all of the energy in the wood is used so there is no waste. The heater burns very clean, and practically no emissions are produced so it is environmentally friendly.

This type of heater, designed and used extensively in Europe, is now gaining popularity in the U.S. The initial cost is more than other types of heating, but due to the savings in energy bills that cost can be recuperated in as little as seven years. The heat is evenly distributed through the home without the use of ductwork or forced air. It is best to design the home around a masonry heater to get the maximum efficiency—homes that have large, open spaces and tall ceilings are well suited for this type of heating appliance.
Added features may be a pizza/bread oven, a heated bench, mantles, heated hot water, and wood storage spaces. A masonry heater should be built by a qualified heater-mason contractor. Find a builder and get more information about how masonry heaters work on the Masonry Heater Association of North America website at www.mha-net.org. 80,000—250,000 BTU output. Cost range- $12,000—$30,000.

Wood appliance safety tips:

 Never install a wood burning appliance in a garage or any area where flammable vapors from gasoline, kerosene, or other flammable products are stored.

 Always have a qualified, licensed professional who knows the NFPA 211 Standards and International Residential Code do the installation. Look for an installer who is NFI or CSIA Certified.

 Keep children and pets away from hot appliances with special gates and guards made for this purpose.

 Keep the chimney and connecting pipes clean and have them serviced annually by a CSIA Certified Chimney Sweep (www.csia.org) to avoid chimney fires and improve the performance of the appliance.

 Keep furniture and other flammable objects at least 36” away from the front and sides of the appliance.

 Do not burn trash, treated wood, railroad ties, colored newspaper, magazines, or pine trees in a fireplace or woodburning appliance as toxic fumes and increased risk of a chimney fire may result.

 Burn your appliance very warm to hot—this means open the damper fully, provide enough combustion air for it to function, and use dense, dry, hardwoods. Read the manual and follow the instructions for the best performance of your appliance.

Resources:

National Chimney Sweep Guild: www.ncsg.org

Chimney Safety Institute of America: www.csia.org

Midwest Chimney Safety Council: www.midwestcsc.org

Masonry Heater Association of North America: www.mha-net.org

National Fireplace Institute: www.nficertified.org

Rumford Fireplaces: www.rumford.com

Hearth, Patio, and Barbecue Association: www.hpba.org

Marge Padgitt is the owner of HearthMasters and Padgitt Chimney & Fireplace in Kansas City, Missouri, and has 27 years experience in the chimney industry. She is a CSIA Certified Chimney Sweep, an NFI Certified Woodburning Specialist and is the Educational Director for the Midwest Chimney Safety Council. She can be contacted at marepadgitt@comcast.net or 816-461-3665.