Pellet Information

All pellets are biomass materials, that is, products of commonly grown plants and trees. The most common residential pellets are made from sawdust and ground wood chips, which are waste materials from trees used to make furniture, lumber, and other products. Resins and binders (lignin) occurring naturally in the sawdust hold wood pellets together, so they usually contain no additives. Nut hulls and other materials are pelletized in some areas, and unprocessed shelled corn and fruit pits can be burned in a few pellet stove designs. Your fuel of choice and its price may depend on the waste biomass most available to pellet mills in your region. In turn, your choice of appliance design depends on the fuel available.

Although the chemical constituents and moisture content of different biomass materials vary, the Pellet Fuels Institute has identified common characteristics and developed fuel standards. These voluntary industry standards assure as much uniformity in the final product as is possible for naturally grown materials that become processed, but not refined fuel. PFI graded fuel must meet tests for:

Density: consistent hardness and energy content (minimum 40 pounds/ cubic foot)

Dimensions: length (1 1/2" maximum) and diameter (1/4"or 5/16") to assure" predictable fuel amounts and to prevent fuel jamming

Fines: limited amount of sawdust from pellet breakdown to avoid dust while loading and problems with pellet flow during operation (amount of fines passing through 1/8" screen no more than .5% by weight)"

Chlorides: limited salt content (no more than 300 parts per million) to avoid stove or vent rusting

Ash content: important factor in maintenance frequency

The first appeal of pellets is their convenience. Bags of pellets stack compactly and store easily. A ton of pellets can be stacked in an area as small as four feet wide, long, and high, an area about half the space needed for a cord of wood. Bags of pellets can be stored in a small area of a dry garage, basement, or utility room or shed.

Pellets are also convenient because they load easily and cleanly into the stove hopper. Loading the hopper is normally required only once a day and may be even less frequent when the stove is used on low settings.

The small size of pellets allows for precisely regulated fuel feed. In turn, combustion air can be regulated easily for optimum burn efficiency since the amount of fuel in the burn pot is predictable and consistent. High combustion efficiency is also due to the uniformly low moisture content of pellets (consistently below 10% compared to 20 to 60% moisture content in cordwood). Uniformly low moisture, controlled fuel batches, and precisely regulated combustion air means high heat output and a very low level of unwanted emissions.

Other environmental benefits besides clean burns result from the use of pellet fuels. As a biomass fuel, pellets offer the advantages of sustainable energy supplies through renewable raw materials. In addition, pellets are a by-product, not a primary user, of these renewable materials. Using pellets also helps reduce the costs and problems of waste disposal. In 1993-94, more than 6.5 million cubic yards of waste were diverted from landfills and converted to home heating in the form of pellets. As part of the tradition of the hearth, pellet burning offers the enjoyment of fire viewing and active participation in providing winter comfort in the home.