Pellet and Corn Furnaces and Boilers
Over the past decade, a quiet revolution has been taking place in Europe and in certain parts of North America, centering on the use of locally-produced wood pellets and corn or corn/pellet mixtures for residential central heat. The increasing popularity of these heaters is largely being driven by high fossil fuel costs, although the perception that these fuels are “green” and renewable is also a factor for some consumers. However the fact remains that until the very recent sharp increases in the price of oil and LP, alternative fuel central heating systems were not in high demand on this side of the Atlantic.
As with chunk firewood and coal, central heating with refined fuels such as wood pellets and shelled corn has a number of advantages over space or “spot” heat typically produced by stoves. It allows the entire house to be heated evenly and respond to the settings of a wall thermostat. The heat can be zoned, allowing for different areas of the house to be heated on demand. Domestic hot water (DHW) can be produced as well, providing additional savings. Central heat also keeps most of the mess and dust of solid fuel in the basement, utility room or outbuilding.
The new generation of pellet/corn appliances is available in both hot air configurations (furnaces) or hot water (boiler) models. All use automatic feeding systems, either from a built-in hopper or an external bin. Typical maximum outputs range from 50,000 to 100,000 BTU (14 to 28 KW) per hour, enough to satisfy most residential heating needs.
Is a pellet or corn furnace or boiler right for you?
An add-on central heating appliance represents a substantial investment, usually costing from $6,000 (hot air) to $12,000 (hot water) for an installed system. Although mostly automatic, you will have to deal with buying fuel, loading pellets into the hopper or bin, removing the ash and general service and maintenance. And you should also have a backup heating system, typically a gas- or oil-fired boiler or furnace, or electric baseboard.
A good starting point for calculating the potential savings or “payback” is our fuel cost calculator here at Hearth.com. Enter the current or projected cost of the various fuels and you will come up with a close approximation of the cost per one million BTU.
A rough rule of thumb on savings over oil can be calculated using the following formula:
Pellets at $275 a ton (delivered) = Fuel Oil at $2.75 a gallon (notice the decimal point is simply moved over two spaces to the left). Since the current (Summer, 2008) price of fuel oil is more than $4.00 per gallon, wood pellets represent almost 40% in savings. Thus, a typical yearly fuel bill of $3,000 would be only $1,800 if wood pellets were burned instead of oil.
Be sure to keep in mind that the prices of ALL fuels can vary widely, in fact they HAVE varied widely in recent years and decades. Calculate your payback conservatively rather than using the highest and lowest prices for the respective fuels.
Most pellet- and corn-fueled central heaters do not require a typical chimney, but instead are “direct-vented” outside the home. If you have an existing, unused chimney, you may be able to vent your new heater into it, thereby saving the expense and labor of cutting through the exterior wall of the house. Be sure to check out some of the hints and tips given on our Pellet Forum (link) including some discussion of the advantages of adding vertical rise to your pellet venting system.
A central heating system is a large and long-term investment and you want to be confident of future service and parts availability. Be sure to check the reputation of the manufacturers and dealers that you consider, as well as how long they have been in business. If possible, check online for reviews and comments regarding the particular appliance you have in mind. Check into the price of pellets and fuel corn in your area as well as the outlook for the future. If you live in a lumber producing region, there are likely to be pellet mills in operation and more planned for the future. Check with a trade group such as the Pellet Fuels Alliance for the mills located near you.
And last but not least—visit the Hearth.com Pellet Mill Forum to discuss your potential purchase with folks who have already been through the buying, installation and learning process.