Everything you need to know when considering a biomass system to heat your home or shop.
When the cold weather hits, the last thing you need to worry about is how you’ll afford to keep the house warm and the pipes from freezing. Since you have no control over the volatile bulk fossil-fuel markets, it’s virtually impossible to budget accurately, unless you look to alternative fuels such as biomass to generate heat. Install a biomass-burning stove today, and you can cut your conventional fuel or electric bill substantially. Make the installation before the end of 2010, and you can get a federal tax credit of up to $1,500 on qualifying models (75 percent efficient).
In the realm of home and workshop heating, biomass-burning appliances are often called biofuel stoves (or furnaces), but in this case, the term biofuel refers to biomass solids as opposed to liquid fuels such as ethanol or biodiesel. Biofuels used for home heating include cordwood; corn, wheat and other grains; wood pellets; sawdust; cellulose pellets made from grass, straw or other plant material; cherry pits or olive pits; and many other renewable and/or recycled materials.
Biofuels aren’t immune to price fluctuations by any means, but since most aren’t traded on the commodities board (except grains), prices tend to be much more stable. Even with grains, the price per heat unit is less than that for fossil fuels (other than coal) most years. Since you are dealing with solid fuels, you can readily purchase biofuels when prices are low and store them for later use – try doing that with your electric utility (though some propane and fuel oil suppliers have off-peak purchase programs where they do the storing).
Whether getting back to basics, doing your part to reduce our country’s dependence on nonrenewable fuels, or trying to economize in heating your home or shop, consider biofuels as you weigh your options. Biofuels are plentiful, sustainable and all around us. Before making the investment in a biofuel stove, be sure to do your homework on efficiency, UL rating and any tax incentives available for specific models. You can begin the process here: http://EnergyTaxIncentives.org/consumers/heating-cooling.php .
Combustion stoves generate heat through the rapid oxidation of fuel producing little more than carbon dioxide and water, under ideal conditions. Biofuels are environmentally attractive because they come close to being carbon-dioxide neutral – carbon dioxide is pulled out of the atmosphere as the plants that create the fuel grow and is released back into the atmosphere when burned. Of course, some petroleum is consumed in the production, processing and transporting of biofuels, so burning them will still result in a small net addition of carbon dioxide into the atmosphere.
The amount of heat produced by a biofuel stove is related to the size of the combustion chamber and fuel feed rate. Manufacturers provide BTU ratings and estimates of the number of square feet each unit is designed to heat.
Your requirement for heat is your first consideration. If you want to heat an entire house, you’ll need a higher capacity stove than you need to heat a single room. As you review specification sheets on interesting models, consider these features: fuel hopper capacity and ease of loading the fuel; type of ignition system (match-lit, starter button or thermostat controlled); what type of thermostat you want (if any); and the manufacturer’s recommendations for cleaning. If you develop a checklist ahead of time, narrowing the choices will be easier.
Sometimes the stove is also a source of ambiance for the home. Many models feature glass windows so the homeowner can appreciate watching a fire while enjoying the heat it provides. In a shop, you’ll likely be satisfied with heat alone, and a more utilitarian model will do.
Before you take the plunge, talk to dealers, neighbors, friends or family members who own biofuel stoves. A little friendly advice can save you valuable time on research and, even more importantly, can keep you from making a mistake on the model you ultimately install.
Fire requires oxygen and will find a way to get oxygen from your house if none is provided directly to the combustion chamber. Efficient modern biofuel stoves are designed to use a source of fresh air from outside your home’s living spaces so the issues associated with sending heated air up the chimney (as with a conventional fireplace) are absent. A biofuel fireplace insert, which installs right into the fireplace opening, is an efficient way to use an existing hearth to heat a room and may save you the cost of installing a chimney or through-wall exhaust vent.
Combustion creates ash. Be prepared to remove ashes from your stove daily if it is a cordwood burner. You can put the ashes in your compost pile or sprinkle them on your shrubs after an ice storm to speed the melting process. Pellet and other non-cordwood biomass stoves tend to create significantly less ash and can be cleaned less frequently. Sometimes ash will melt, then reharden into clinkers – clinkers can clog the combustion chamber, and they need to be removed promptly when they occur. Using premium-grade pellets can reduce the maintenance required, but your stove will still require weekly, monthly, bimonthly and annual cleaning. For models with glass, the smoke residue occasionally will need to be cleaned off the glass. If you cannot tolerate this extra work or the dust a stove can generate, you might not find the savings worthwhile.
Electricity and propane are the most convenient ways to heat when your place is far from natural gas lines; they are also the most expensive. Electric heat will be, on average, twice as expensive as heating with a biofuel stove. Although prices vary from region to region in the United States, wood, pellets and corn (subject to some market volatility) are all similar in cost per million BTUs. Pellets and corn are about 20 percent more efficient than wood. What fuel is most plentiful and least expensive in your area? Besides capacity, type of fuel is probably the most important consideration when deciding on a biofuel stove. If you stick with a fuel that is plentiful in your area, your heating needs will be less affected by volatile markets and fuel shortages.
• Pellets are made from recycled wood waste, primarily compressed sawdust. According to the Pellet Fuels Institute, there are more than 800,000 households in the United States using wood pellets for heat. Depending on the size of your home, your climate and the temperature you prefer, two tons of wood pellets should last one heating season. Some families report using half of that or less, and some use twice as much.
Pellet stoves are wood burners with an automated feeder system that moves the fuel from the hopper to the combustion chamber. The stove maintains the optimum fuel-to-air ratio, resulting in minimal smoke emissions and maximum combustion of the fuel. A power venting system further automates the system. Dozens of models of pellet stoves are available. Hopper capacity ranges from 50 to 76 pounds, and hopper extensions can nearly double the capacity.
On its website, the Pellet Fuels Institute (703-522-6778, www.PelletHeat.org ) lists 68 pellet manu-facturers in the United States. Pellets are widely available at many home and garden centers and larger home improvement retail stores. Shop around and consider purchasing a tractor-trailer load of pellets with a few friends for the ultimate in savings. Bags of pellets are easy to store on pallets in your garage.
• When corn became the darling for ethanol production, the price shot up to about $8 per bushel and has fluctuated widely since then. You can expect low-moisture shelled corn to cost between $113 and $286 per ton. At its high point, corn was more expensive than most stove owners were willing to pay – that price spike was short lived and largely due to the activity of corn futures speculators.
“We used to mix corn 50-50 with pellets for a hotter fire,” says Colorado resident Sherron Hudson. “But the price got so high, we just use pellets now.”
Many corn stoves are actually multifuel appliances that will burn shelled corn, barley, wheat, wood pellets and wheat chaff. These stoves allow owners a broad spectrum of fuels, which is ideal for someone who lives in an area of agricultural production and can grow her own or go directly to the farmer for the grain. If you choose this route, you will need to have a good place to store bulk fuel grains. According to Mike Gott, an authorized dealer for biofuel stoves in Colorado, burning grains also produces significantly more ash than pellets, with corn topping the list.
Most multifuel stove hoppers hold between 50 and 80 pounds, and extensions are available. A quality, properly installed multifuel stove may hedge bets against price fluctuations among different biofuels.
• Cordwood-burning stoves have improved steadily over the years in efficiency and safety, and burning wood for heat is still a viable option in most locations. Cordwood handling is a little messier than many other biofuel options – loose bark, debris, insects and dirt can all come into the house with a load of firewood. Even though wood stoves require more attention, the fuel itself can be harvested from your own woodlot for the cost of cutting and splitting. If you don’t have your own source, firewood can also be purchased from a local woodcutter out of season for considerably less than the cost of a comparable amount of heating oil, electricity or natural gas.
Plan to install your stove in the area of your home where your family members spend most of their time. The stove’s manual will specify how far from combustible materials the stove can be installed. Sometimes the required clearance is as modest as three inches. In the home or shop, the stove must be installed on a fireproof hearth pad. It also needs to be installed near an electrical outlet to supply power to the feeder, fans and combustion air system.
If you are a skilled do-it-yourselfer, you can install a biofuel stove. You will need a brawny helper, because units can weigh between 180 and 390 pounds. The envelope of the home will need to be breached for the flue and to draw fresh air into the combustion chamber. Check your local building department to see if a permit is required. For many reasons, you may want to have a professional do the job for you. If a dealer installs your stove, he will warranty the work. No matter what type of stove you choose, make sure you select a reputable dealer who will be there when you need repairs or assistance.
It is vital that the installation be done properly. Improperly installed units will not work as efficiently and can present a danger to your family. Ductwork must be properly sized for the stove to operate at peak performance. For safety’s sake, install detectors for smoke and carbon monoxide. Chimneys for all stoves should be inspected annually and cleaned as needed.
A biofuel stove is an investment that allows you to use less fossil fuel for heating, while saving money each heating season. In return, biofuel stoves require a commitment of time and a more active role in the process of heating your home or shop. If you have a ready source of fuel and are prepared for the extra work of cleaning your appliance to keep it in good working order, biofuels may be right for you.
Carol Dunn grew up reading GRIT in rural Pennsylvania. After getting her fill of city living, she is finally back in the country on a 35-acre farm in southern Colorado with her husband and daughter. She writes regular columns on rural living, gardening and humor for her local newspaper.
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