Woodburning's new age.
Motivated by the shortage and high prices of fossil fuels in the 1970s, Americans turned in droves to wood heat, but all those puffing flues produced a lot more than energy independence. Scientists soon discovered that woodsmoke contains a pharmacopeia of noxious agents-including formaldehyde, carbon monoxide, hydrocarbons, and polycyclic organic matter-and that woodstoves were spewing millions of tons of these pollutants into the air annually. Some of the compounds are carcinogenic, and others cause respiratory problems. All contribute to a sunblocking, lung-irritating, spirit-depressing malaise known as winter haze.
Many communities-first in the mountain West but later across the country-began choking on the seasonal woodsmoke pall. Schools kept kids inside for recess. Neighbors battied neighbors over smoky trespass. Pollution readings became nightly fare on TV weather shows. In some places, regulations prohibited fires during the worst episodes, and a few defiant or careless homeowners got fined for burning wood. One community even put a red light on everyone's fireplace and a temperature sensor in the chimney to warn against and detect illegal woodburning.
In 1986, Oregon prohibited the sale of the most polluting stoves, and other states prepared to follow suit. That same year, the federal Environmental Protection Agency joined the fray when New York State and the Natural Resources Defense Council threatened to sue the agency for failing to keep the country's air clean. For a time, it appeared that the entire woodstove industry and wood-heating way of life might be torn asunder in the battle for clean air.
But where chaos once threatened, order now is rapidly returning. In 1986, the EPA, environmentalists, scientists, and state agencies sat down to establish standards for new stoves. They were even joined by the stove industry-in the form of its 800member Wood Heating Alliance (WHA) trade organization. "We wanted to avoid a proliferation of diverse state restrictions," says WHA's technical director Gary Satterfield. "As long as there were going to be standards, we wanted a single federal regulation." During several months of negotiations, the participants hammered out mutually acceptable rules that pleased no group completely. "Naturally, we would have preferred different [less restrictive] numbers, but it's a workable standard," says Satterfield.
EPA regulations prohibit the manufacture and sale of woodstoves that cannot pass a stringent emissions test. Open fireplaces, wood-fired boilers or furnaces, and wood cookstoves are exempt from the regulations, but fireplace inserts and airtight" fireplaces with gasketed doors are included.
Homeowners with old stoves can rest easy, however. "The EPA has no intention of regulating the installation or use of woodstoves," says the agency's Bob Lebens. States, counties, or municipalities may do so, however). As of August 1989, 212 stoves had passed muster with EPA, and 74 of those already meet the agency's tough Phase 11 requirements.
A woodstove pollutes the air when it burns its fuel incompletely and inefficiently, sending unburned gases up the chimney in the form of smoke. To reduce smoke, prevent air pollution, and earn EPA certification, stove makers invariably rely on one of three distinctly different new technologies-catalytic combustors, pellet fuel, or the redesign of existing airtight models.
Catalytic combustors (spinoffs of automobile catalytic converter technology are probably the biggest news in "Defending Your Dogwoods" below). woodburning since the match. One hundred and eleven of the 212 EPA-certified stoves use a catalyst to cut emissions. A typical catalytic combustor is a honeycombed ceramic cylinder about six inches in diameter and three inches high. The surfaces of the honeycomb have been coated or impregnated with a rare metal catalyst, usually platinum or palladium. Inside the stove, the combustor is positioned so that smoke must pass through the honeycomb to escape into the flue.
Smoke consists of combustible gases that will ignite at about 1,000 degrees. (All temperatures are given in Fahrenheit.) Unfortunately, the fire in most black-box airtight stoves never gets much above 600 degrees, which means that a lot of pollution and lost energy escape up the chimney. In the presence of the catalyst, however, smoke burns at 500 degrees instead of 1,000. To the uninitiated, it sometimes seems more like magic than science.
Once a catalytic combustor reaches its "light-off" point of about 500 degrees, it continues to burn nearly all the smoke passing through it. The more smoke it consumes, the hotter it gets, and the hotter it gets, the more smoke it consumes. Combustors cruising along at 1,600 degrees may glow orange with heat. And since the combustor thrives on a diet of smoke, it's permissible-even desirable-for the homeowner to maintain the kind of slow, smoldering fire that would send huge amounts of smoke belching from any noncatalytic stove.
Catalytic stoves have always tested well in the laboratory, but for a time doubts lingered about how well they actually performed in the home. "There's no longer any question about a catalytic stove's ability to greatly reduce pollution," says Skip Barnett, manager of an in-home woodburner study done by Omni Environmental Services, a major stove-testing firm. "In fact, one of the catalytics in our study performed just as well in a home as it had under ideal lab conditions, and that's rather remarkable. " Experts now agree that a catalytic combustor in a well-designed stove can reduce pollution from that device by 90 percent.
Another soldier in the wood-heat revolution is pellet fuel-and the devices that burn it. A few years ago, entrepreneurs in the Northwest began turning waste wood from lumber mills into a new form of pelletized firewood. Pellets consist of wood chips, sawdust, bark, and other scraps that have been dried, pulverized, and compressed into tiny cylinders about one inch long and a quarter-inch in diameter. The fuel looks a lot like feed-store rabbit food, and according to the Association of Pellet Fuel Industries, a ton of pellets has about the same heating value as a cord and a half of firewood. The fuel typically is sold in 40- or 50-pound bags, and prices may range from $80 per ton at a pellet mill to more than twice that amount 200 miles away.
Because pellets contain only about 5 percent moisture (versus 25 percent or more for seasoned cordwood), they're capable of burning very cleanly-in the right device. Which means a stove designed especially for that purpose.
Most of them work like this: a hopper near the top of the stove holds about 80 pounds of pellets. An electric auger slowly trickles the fuel from the hopper to a diminutive firebox, where an electric fan forces air into the fire. The result is a small, hot blaze. Another electric fan carries the heat away from the stove and into the room.
The pellet idea smoldered for a while with only regional interest, but in the new era of clean-burning stoves, pellet fuel has really taken off. At last count, about 30 mills in 14 states were making pellet fuel, and about two dozen manufacturers make pellet stoves. Hotbeds of interest are in the Northwest and Midwest, but Vermont, Tennessee, California, and other states also have pellet mills. "Eventually, every community will have at least one pellet-stove dealer and every grocery store will sell pellets," predicts Larry Roberts, secretary of APFI. "This industry is literally on fire. "
Cleanliness is probably the pellet burner's strongest selling point. Combustion in these devices is so complete that often the only flue needed is a small class L vent (similar to that of a natural-gas furnace). Seven of the 10 cleanest-burning stoves are pellet burners , and two of these emit an incredibly minuscule 0.5 grams of particulate per hour. Electricity use by auger and fans is said to be minimal as well-one stove maker compared it to a pair of continuously burning 100-watt light bulbs.
Another major advantage is ease of operation. All a homeowner has to do is fill the hopper with pellets every 15 to 80 hours. Some models even come with a wall thermostat that regulates heat output. A thermostat helps eliminate the overheating problem associated with woodburning. Even without a thermostat, however, pellet stoves generally provide a very even heat, primarily because fuel is fed into the firebox at a predictable rate.
Pellet burners are not for everyone, however-especially those who treasure the sweaty satisfaction of gathering their own wood. And, of course, the fans and auger make these devices dependent upon electricity. No power means no fire. "You might as well pipe in natural gas," groused one purist.
The third kind of clean-burning stove is a fine-tuned version of the one you're probably using now. No new fuels or magical catalytic chemistry here. Instead, manufacturers have taken their airtight models and tinkered and experimented and modified until the stoves operate at the highest possible efficiency and produce the least possible pollution.
The most common technique is to make the firebox appreciably smaller than that of most airtight stoves, which tends to increase the temperature and ignite more smoke.
"There seems to be an optimum firebox size of about 1.8 cubic feet," says Steve Crane of the Oregon Department of Environmental Quality. "Stoves larger than that are likely to have more emissions, and smaller stoves are not as convenient to use." Many of the cleanest-burning stoves of this type do, however, have fireboxes smaller than 1.5 cubic feet.
Manufacturers also have studied thoroughly the dynamics of air flow inside the stove. In older stoves, smoke often travels from wood to chimney in pretty much a straight line, which means that a lot of it escapes unburned. By adding baffles, plates, and secondary air inlets at strategic spots, stove makers create extra turbulence inside the firebox. And when smoke churns around inside a stove, it's more likely to get burned.
Another ploy is to increase firebox insulation, usually with additional or more-heat-resistant brick. This can boost the stove's internal temperature and cause more smoke to ignite. A few stove manufacturers also make their devices "foolproof" by making it impossible for a homeowner to close the draft past a certain point.
The result of all these machinations can be lowered emissions. Many of the high-tech, noncatalytic stoves (as they're called) have met EPA standards, but they generally come in behind catalytics and pellet burners in the pollution-reduction race. Sometimes they have other drawbacks as well. The small firebox size means frequent feeding and ash removal. All-night burns are largely a thing of the past. And too much insulation on a stove can send valuable heat up the chimney instead of into the room. Few of these devices could be considered convenient whole-house heaters.
In addition to being technically difficult, reducing woodstove pollution can be expensive. High-tech, noncatalytic models start at about $600, and the most pricey pellet burner tops out at about $2,300. Catalytic stoves fall in between, but catalytic combustors must be replaced after about 12,000 hours of use at a cost of $50 to $100. Most high-quality EPA-approved stoves, regardless of technology, cost between $750 and $1,400. "EPA's involvement in all this probably adds about $200 to the cost of a catalytic stove and $120 to a noncatalytic tic," says the agency's Bob Lebens. However, some of that extra expense may come back to the homeowner via less frequent chimney cleanings and reduced firewood consumption. Good catalytic stoves, for example, have been known to cut wood use by 30 percent.
"In the long run," says Lebens, "a clean-burning certified stove may actually be cheaper than one that is initially less expensive." In addition, the EPA predicts an annual reduction of $1.5 billion in health costs and property damages resulting from exposure to woodsmoke.
If you'd like to step with just one foot-and less expense-into the new age of woodburning, you can do so by modifying your present stove. A device called the Collins Hopper-complete with bin, auger, and fan-turns almost any black-box stove into a pellet burner. Hoppers sell for about $600.
To go catalytic, you can install in your lower flue one of the several add-on catalytic combustors, devices that have been around for several years without really catching on. "Maybe that's because most of them make the flue look like an ostrich that has swallowed a baseball," jokes Dave Collier, a stove-certification analyst with the Oregon DEQ.
Last winter, the DEQ tested add-on combustors and came away optimistic. "They can't reduce emissions the way a well-designed catalytic stove can, but we were generally pleased with their performance," says Collier. "They seem to be a good idea that hasn't fully developed yet." Catalytic add-ons generally sell for about $250.
The latest woodstove revolution also has changed some of woodburning's basic tenets and traditions. Pellet fuel, of course, is an entirely new ballgame with its own set of rules. The high-tech, noncatalytic stoves often require more frequent attention and shorter logs. And even if a stove can hold a fire overnight, it's generally considered antisocial behavior these days to burn a slow, smoky fire.
The greatest changes, however, involve catalytics. With these stoves, moisture content and wood species suddenly don't make a difference any more. In fact, wood that is slightly wet often works best because it creates more smoke, which is what catalytic combustors feed on. Really dry wood, on the other hand, may burn too fast and overload the catalyst.
In addition, burning wood that has been painted, pressure treated, oiled, or impregnated with creosote can destroy the catalytic combustor. So can artificial logs, colored paper, and chemical chimney cleaners. Essentially, the only things that should go into a catalytic stove are natural wood and regular (black and white) newspaper.
And speaking of creosote, its buildup in chimneys and pipes is largely eliminated with the new low-pollution stoves. Reductions of up to 90 percent have been reported.
Appearance is very much a part of the woodburning revolution too. The black box has given way to a dazzling array of more than 700 stove models with sweeping contours, porcelain or ceramic finishes, decorator colors, and chrome, silver, or gold trim. Some look like antiques, others like spaceage furniture. One pellet stove comes encased in a brass-trimmed, varnished oak cabinet, and another boasts computerized controls. Many new stoves feature glass doors, and most manufacturers have figured out how to keep them free of soot (usually by sending a stream of air over the interior surface).
But what of woodburning's ambience? Are the independence, the self-reliance, the cozy glow still intact? In going from art to science, has woodburning lost its appeal? The resounding answer appears to be "no. "
"Wood heating is alive and well," says Diana Takvam of the WHA. If anything, the new technology has improved things by removing any guilt that may have existed and by making the appliances increasingly attractive. "The warm, genial ambience of wood heat is still intact," says Takvam. "A wood fire has always been the heart of the home, and that feeling isn't about to go away. "
The Greenhouse Connection
As more and more of America's 12 million wood-heated homes switch to new-generation stoves, the air should become noticeably cleaner. In the long run, however, another aspect of heating with wood may prove to be more important environmentally.
Decades of burning fossil fuels have pumped huge quantities of carbon dioxide into the atmosphere, where the gas acts as a blanket to insulate the earth and cause it to warm. Many scientists agree that global warming-the greenhouse effect-will become the premier environmental issue of the decades immediately ahead.
Using wood for heat instead of coal, oil, or natural gas can help slow this trend. Trees sequester large quantities of atmospheric carbon dioxide as they grow. On average, a single tree absorbs about 26 pounds of carbon dioxide in a year-five tons annually for every acre of forest. Although the carbon dioxide is released when the wood is burned, it can be -recycled' by the simple act of replacing those cut trees-a step that is not possible with nonrenewable resources like oil and gas.
The key to this replacement is replanting on a large scale. "It's not good enough just to burn wood,- says Bob Kwartin of the Environmental Protection Agency. Those trees must be replaced with new ones. - Now that woodstove emissions will soon be in check, the EPA is recommending a sharp increase in wood fuel as part of the multifront battle against global warmimg. Some members of Congress have even included praise of wood heat in environmental legislation-a big switch from the criticism prevalent just a couple years ago.
(Emissions in grams of particulate per hour)
VENTURI PVI-87 0. 5 g/h
CROSSFIRE FS-1 0.5 g/h
DEFIANT ENCORE 0. 6 g/h
Vermont Castings, Inc.
P-1000W 0. 7 g/h
Welenco Manufacturing Inc.
WHITFIELD FIREPLACE/ 1.0 g/h
Pyro Industries, Inc.
SCHRADER 1.0 g/h
Evergreen Metal Products, Inc.
INTREPID II 1. 0 g/h
Vermont Castings, Inc.
ERIK SW II CATALYTIC 1.2 g/h
American Road Equipment Co.
WHITFIELD WP-1 1.3 g/h
Pyro Industries, Inc.
WHITFIELD ADVANTAGE 1.3 g/h
Pyro Industries, Inc.
C. D. LARGE FEDERAL 1. 6 g/h
Vermont Castings, Inc.
BLAZE KING CATALYTIC 1.9 g/h
Woodcutters Manufacturing, Inc.
ACHIEVER FPI-1-LEX 2.O g/h
Derco, Inc./Grizzly Stores
3-C 2. 0 g/h
CATALYTIC TILE FIRE 2.0g/h
Kent Heating Limited
WINTERWARM 1280 2. 1 g/h
Vermont Castings, Inc.
BLAZE KING CATALYTIC 2.2 g/h
INSERT KEI 1300
Woodcutters Manufacturing, Inc.
Sierra Manufacturing Company
of Virginia, Inc.
Smoke By The Numbers
To meet Environmental Protection Agency requirements, a manufacturer must send a stove from each of its model lines to one of eight EPA-certified commercial testing laboratories. There, stoves are fired up and the particulate emissions (solid, unburned hydrocarbons) are measured. Additional components of woodsmoke could also be gauged, buy low pollutants are scarce too. EPA's benchmark is the number of grams of particulate given off during an hour of burning (g/hr). Stoves that fail the test cannot be manufactured.
The EPA is implementing regulations in two phases. Phase I covers stoves manufactured between July 1988 and July 1990. Catalytic stoves made during this phase may emit no more than 5.5 g/hr and noncatalytic stoves no more than 8.5 g/hr. Phase II covers stoves manufactured after July 1, 1990. During this phase, catalytic stoves may emit no more than 4.1 g/hr and noncatalytic stoves no more than 7.5 g/hr. Catalytic stoves have more stringent testing requirements because the catalyst gradually degrades over time and later emits more particulates than when it was new.
Following th implementation of each phase, there is a two-year "grace period" during which existing inventories of noncomplying stoves may be sold. Consequently, the regulations will first be felt at the retail level on July 1, 1990, when all stoves sold must meet Phase I standards. After July 1, 1992, all stoves sold must meet Phase II requirements. All EPA-certified stoves will be labeled as such.
"Buyers should be aware that low-emission stoves usually don't burn as cleanly at home as they do in the lab," warns Steve Crane of the Oregon Department of Environmental Quality. "Catalytic combustors deteriorate, baffles warp, gaskets crack, and dampers stick." Although the grams-per-hour figures mentioned above may not be achieved at home, they do provide a good basis for comparing stoves - much as miles-per-gallon tests are used to compare fuel efficiency in automobiles.
Still, the new clean-burning stoves represent a fantastic imporvement over existing airtight stoves that may pump 35 to 70 grams of particulate into the atmosphere each hour. Overall, the EPA requirements are expected to reduce woodstove pollution by a whopping 70 to 90 percent.
Over the past year, support has been growing for the Forest Stewardship Program, a new initiative to encourage integrated resource management on our nation's nonindustrial private forestlands.
In December 1988, the National Association of State Foresters (NASF) and the State and Private Forestry S&PF) branch of the U. S. Forest Service agreed to work together to obtain Congressional funding for this initiative. It appears as if their efforts have been successful. Both the Senate and the House of Representatives have included funding for the Forest Stewardship Program in their versions of the fiscal 1 990 Forest Service appropriations bill.
Conferees from the House and Senate will soon decide how much funding to provide. The amount is likely to fall between the $5 million and $15 million figures proposed by the House and Senate respectively.
The purpose of the Forest Stewardship Program is to reach the many owners of nonindustrial private forestland who have not been engaged through traditional forestry-assistance programs. The program is also intended to encourage them to better manage their lands for a broad array of resource values over the long term.
Fifty-eight percent of our nation's commercial forestland is owned and managed by nearly eight million owners of nonindustrial private land. Traditional efforts to provide professional technical assistance have reached only about 10 percent of these owners, and of those harvesting timber, fewer than 30 percent have done so according to a professional management plan.
Additional objectives of the program include the following: to be more responsive to landowner needs, which are often expressed in terms of wildlife, timber, aesthetics, and stewardship (i.e., properly managing land to leave it to one's heirs in better condition than it was received); to place an equal emphasis on environmental and economic management principles; and to develop truly integrated management plans that focus on fish and wildlife habitat, water quality, soil productivity, aesthetics, wetland management, and recreation, as well as timber management-for tile benefit of current and future landowners, as well as for society at large.
One of the key program elements is encouraging increased cooperation and coordination among federal and state agencies in providing a broad range of professional technical assistance to landowners.
The goal of tile Forest Stewardship Program is to enroll 25 million acres of nonindustrial private forestland across the nation with in the next five years. To accomplish this goal, NASF and S&PF are seeking $15 million this year and $25 million in each of the next four years. These federal funds are to be matched by state and local funds.
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|Title Annotation:||includes related information|
|Date:||Nov 1, 1989|
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