Heating with a wood pellet stove

Besides the ubiquitous wood stove, the pellet burning stove is another heating method that uses a renewable energy source. These devices are used in industrial heating applications, as well as home heating. For home heating applications, they can be purchased in furnace form, and most commonly in a variety of forms for supplemental heating, such as fireplace insert and freestanding models. Some can burn a variety of wood pellets and corn as fuel. Some can be thermostatically controlled, allowing attention-free operation. These stoves provide a warm, cozy ambience, and are reasonably clean, compared to the standard wood burning stove. Pellet stoves are not 100% clean, as some fine dust and ash is inherent in their use.

Freestanding Pellet Stove
Credit: frederick.forestryboard.org - David Barrow

The pellets come in a variety of sizes, styles, and cost, depending upon their intended use. The organic pellet fuel is available from a variety of sources and varying prices. These pellets are generally made from compressed sawdust or other biomass that is normally surplus from lumbering or other similar operations. Pellets for home use are usually sold in a 40 pound bag size, and the cost is typically around $250 a ton. A pound of good quality hardwood pellets normally yields 1750 BTU. Wood logs normally provide a higher BTU output, but it is difficult to make a direct comparison due to variations in wood type and moisture content. Pellets are normally very dry and provide a near constant heat output. Typically, the stove auger regulates the pellets based on demand. They are burned hot, thus minimizing the creation of creosote, which can create dangerous chimney fires.

Pellet stoves are complex devices with an electric igniter, multiple sensors, blowers, motors, an auger, and safety devices that are intended to prevent the introduction of dangerous combustion products into the home. The combustion process is generally very efficient, emitting small amounts of particulate into the environment. They are efficient and yield a surprisingly minimum amount of ash as a combustion byproduct. Normal consumption of pellets in a typical supplemental heat application would be about a bag or so a day. Compared to the difficulty of regulating the heat output desired from a log burning stove, the pellet stove is understandably much more efficient.

Pellet stoves are not maintenance-free, and require a regular schedule of maintenance to retain their efficiency and safe operation. Depending upon the agility and age of the maintainer, care should be given to the type of stove and its placement. In general, free standing devices are easier to get to critical maintenance items. Typically, the stoves require daily maintenance, such as scraping and loosening the carbon buildup around the edges of the burner pot. Weekly, it would be good to vacuum out the fly-ash and soot from the heat exchangers and combustion fan areas. This is not difficult, but requires a completely cold stove, and a dust-free shop vacuum should be used. A more thorough cleaning is needed after the burning of a ton of pellets and yearly cleaning of the exhaust outlet, pellet auger, and chimney flue is needed. Maintenance data provided with the stoves varies, and there are many on-line sources of cleaning and maintenance information available.

Pellet Stove fireplace insert
Credit: Unknown

The pellet insert shown was chosen to replace a wood stove that had been used for many years. Wood stoves are very dirty, compared to this stove. With a wood stove, wood has to be carried into the house, along with the mess and detritus that falls from even clean, well-seasoned wood. The area surrounding the wood stove also required constant cleaning after fueling. The pellet stove is also more convenient, in that it can start and stop automatically, as needed.

The heat output desired from the pellet stove is much more easily regulated, and the stove can maintain room temperature within a few degrees.

Article by Claude Eans Frederick County Forest Conservancy District Board members