More Folks are Warming Up To the Virtues of Pellet Stoves
JAFFREY, N.H. — Steven Walker remembers the first time he picked up a handful of wood-stove pellets and let them trickle through his fingers.
The fuel efficiency, the cleanliness, the environmental benefits, as well as the light-it-and-leave-it convenience the pellets brought to the cheery comfort of wood-burning - all struck home in an instant. "I was blown away" by the whole concept, he says.
Later, Mr. Walker was amazed to find that the nearest supplier of wood pellets was almost 2,000 miles away. "Why," he said, visualizing the mounds of waste sawdust plaguing manufacturers around New England, "I could make these for you right here!"
Walker, a machinery and robotics expert and onetime building contractor, had gone into the shop simply to check out wood stoves. When he left, it was with the realization that his business career was about to take a dramatically different tack. That was eight years ago.
Today, Walker is chief owner-operator of New England Wood Pellets Inc., one of 80 companies nationwide supplying the now 500,000 home owners in the US (including this writer), who use pellet stoves to heat their homes.
People are steadily being drawn to pellet stoves, first introduced in the early 1980s, because they get the classic comfort and charm of wood burning with few of the old-fashioned inconveniences like the constant need for stoking, creosote buildup, and occasional smoky back drafts.
Here's how they work: Pellets, about 1/2-inch long and the thickness of a pencil, are loaded into a hopper, from where they are automatically fed, a few at a time, into the fire. One 40-pound bag of pellets will last about 24 hours in most homes; in my small Cape, somewhat longer than that.
A fan heats the home by blowing air through heat exchanger tubes and out into the surrounding room. Output is adjusted by the rate at which the pellets are fed into the grate. In some models this adjustment is thermostatically controlled. Automatic ignition is another recent feature on some models along with battery backup power in the event of an electrical outage.
Pellet stoves also address many of the environmental concerns relating to wood burning. Air, forced through the grate, results in the most efficient burning possible. As a result, the stoves produce virtually no emissions or creosote. Tests show that the stoves burn close to three times cleaner than the strictest Environmental Protection Agency standard of 4.1 grams of particulate matter per hour.
I have stood alongside the chimney on the roof of my house and detected no sign of smoke or marked smell of burning normally associated with a wood fire. When I placed my hands directly over the chimney, the gentle warm updraft washing through my fingers indicated how little of the fire's heat was escaping.
Ash is minimal
Because they are so clean burning and because so little energy escapes as wasted heat, pellet stoves do not have to be hooked up to a conventional chimney; a vent pipe 4 inches in diameter is all that is required. Ash is minimal. At the height of the heating season, I seldom have to remove more than a cup or two of ashes every few days.
But there is a down side, if such it can be called, to all this efficiency. Unlike the conventional wood stove, the pellet stove is more than just an inert iron box. It is a machine with electronic controls and moving parts. For this reason, it's best to have it serviced once a year - at a cost about equal to the amount you won't have to pay out to have your chimney cleaned.
A happy collaboration
The almost 15-year-old pellet-stove industry might never have come about but for an almost chance meeting that brought two men together in the late 1970s - one who recognized that machinery that turned alfalfa into pelleted cattle feed could be modified to do the same thing with sawdust and another who designed a stove that could use the new type of fuel so efficiently.
Ken Tucker, founder of Lignetics of Idaho, began experimenting and making batches of wood pellets with the thought that industrial furnaces might be able to use them. But the idea wasn't panning out too well when Jerry Whitfield, a fuel-efficiency engineer from the Boeing Corp. came by.
Mr. Whitfield, with a background in fluid-bed furnace technology, had been assigned to search for alternative fuels. If, so the rationale went, alternative fuels, wastes in particular, could be found to power the industrial furnaces of this world, that much more oil would be freed up for the airline industry.
The investigation had not long been under way when someone suggested he look up a fellow named Ken Tucker in Idaho. When the two met, Whitfield quickly realized that the tiny wood pellets would be an ideal fuel for small household furnaces and, perhaps, even wood stoves. He also realized that the oxygen-enriched environment that made fluid-bed industrial furnaces work so efficiently could be introduced to small pellet stoves by directing jets of air into the grate.
Tremendous heat could be extracted from just a few pellets at a time as they were introduced into the fire. The furious burn rate caused by the jets of air would also mean that the fire would burn very cleanly.
And so, in 1983 the first Whitfield pellet stove was introduced to the wood-burning industry. Slowly the idea has caught on, and today some 20 companies around the world make pellet stoves and home furnaces.
Nowhere have pellet stoves caught on more rapidly than in Sweden. In fact, Sweden now uses more pellets to heat homes, schools, and offices than does any other nation, overtaking the US in 1996.
Corn stalks will do, too
More recently China, New Zealand, Russia, Italy, and South Africa have expressed interest in pellet stoves.
"Any country that produces adequate amounts of combustible waste will benefit from the technology," says Whitfield. Wood waste is best but any biomass will do. Corn stalks and cobs, ground and compressed into pellets, "work very effectively," he says.
But, could the day come when the US runs short of sawdust waste for the burgeoning industry? "Not for well into the foreseeable future," says Whitfield. The nearly 1 million tons of wood pellets now being produced each year in the US "have barely scratched the surface," he adds.
Meanwhile Walker, who says 80 miles is the maximum distance sawdust can be economically trucked for pelleting, is crunching numbers for another production facility.
"If we can't bring the sawdust to the factory," he says, "we'll take the factory to the sawdust." In his view, there's only one thing for the wood-pellet industry to do - expand.