[BI ED. "One wood boiler can produce the emissions of 205 oil furnaces and 20 indoor wood stoves, according to a 2006 report from the Northeast States for Coordinated Air Use Management, a 40-year-old independent group."]
FOR three decades, Robin Norton of Bethany, Conn., heated her 2,000-square-foot home the way many people do: by burning oil. In 2004, though, fed up with the $1,200 annual bill, Ms. Norton, an emergency medical technician, switched to a wood-fired boiler.
Tucked into a shed in her nearly four-acre backyard, the dishwasher-size unit sends hot water through pipes into her house, where it is converted to enough hot air in winter that she keeps the thermostat set at 74 degrees. But the system can also warm a pool "so my grandkids can swim in April," she said.
The Nortons are part of a small but growing number of families who use wood-fired boilers and wood stoves to heat their homes; sales are up 20 percent a year for the last four seasons, vendors in the metropolitan area say.
Sales have risen despite environmental concerns. Wood-fired boilers can generate thick smoke round the clock throughout the year, and some municipalities have restricted their use.
Ms. Norton did suffer a few pangs of guilt when she bought her boiler, although not for environmental reasons; her husband, Chip, works for a heating-oil company. They were quickly eased by their oil bill last year: $7. And that was pricier than the wood, which loggers give them free.
"We would be freezing otherwise, now that oil costs over $3 a gallon," she said.
New York's state average as of Jan. 21 was $3.48 a gallon, about 40 percent higher than the mid-January rate of $2.48 last year, according to the Energy Information Administration, a division of the federal Department of Energy.
For homeowners looking for alternate fuel sources, wood is gradually becoming more popular, according to census data. Wood is winning out over oil, propane and natural gas, vendors of wood stoves say, whether the new units are traditional log-burning kinds or the more environmentally friendly versions that use sawdust pellets.
Wood stoves and boilers are often used in conjunction with oil furnaces and tend to be found in rural areas, census records show. These areas have more single-family homes than apartments; boilers need yards, while stoves can require special chimneys.
In Hudson County, N.J., and Nassau County, N.Y., for example, boilers are practically nonexistent, American Community Survey census records show.
But from 2003 to 2006, more homes in Fairfield County, Conn., and Westchester, Orange and Putnam Counties in New York used wood for heating, while in New Jersey, Bergen, Essex, Middlesex, Morris, Passaic and Union Counties saw upticks. Those areas totaled about 7,500 wood-heated homes in 2006, the data show.
Wood-burning homeowners say the savings are considerable once they pay off the equipment, which can cost $3,000 to $5,000 for a new stove or boiler, and a few thousand dollars for installation. The cost of a month's supply of wood can run a quarter of that of oil, the difference between $200 and $800, and even less if a homeowner cuts or collects the wood.
Plus, in a time of collective guilt about energy consumption, wood may have an old-fashioned feel-good quality about it.
But critics say wood smoke contains potentially hazardous grit, which is practically invisible yet can damage lungs if inhaled.
Although cars and power plants also generate these harmful particles, wood smoke in Connecticut in winter accounts for up to 38 percent of the particles, said Alison Simcox, who studies the state's air quality for the Environmental Protection Agency.
One wood boiler can produce the emissions of 205 oil furnaces and 20 indoor wood stoves, according to a 2006 report from the Northeast States for Coordinated Air Use Management, a 40-year-old independent group.
"Many people do not grasp the pollution potential of this source, and I feel like a killjoy when I talk to them about it," Ms. Simcox said. "But southwestern Connecticut is getting blanketed by wood smoke, and it's significant."
This pollution is particularly dangerous in winter, when cold weather traps smoke in valleys, said Peter Babich, a state environmental analyst with the E.P.A.
"And fuel prices aren't getting cheaper, so it will continue to be more of an issue," he said.
Since 1988, the agency has imposed emissions standards on indoor stoves to cut down on particles, though wood boilers have been tougher to regulate.
In 2005, the Connecticut Legislature's effort to ban them was shot down under aggressive lobbying by the Hearth, Patio and Barbecue Association, a Virginia-based trade group representing manufacturers, local legislative and industry officials said. But the legislative effort did result in new rules, including that boilers must be 200 feet from neighbors' houses and that no painted wood can be burned.
Suffolk County on Long Island passed a law in 2006 that restricts boilers' use to colder months, and not near hospitals and schools, until the beginning of 2010, when they will be banned outright except for natural disasters.
All told, 62 counties, towns or villages in New York have banned or restricted wood-fired boilers. Most are upstate, though the list includes Warwick in Orange County and all of Rockland County; Rockland will adopt whatever regulation is passed by the State Department of Environmental Conservation, which is "reviewing proposals now," said Yancey Roy, a spokesman.
No New Jersey towns have restricted or banned wood-fired boilers, and no proposals are before the Legislature, said Darlene Yuhas, a Department of Environmental Protection spokeswoman.
For their part, boiler-makers agreed last year to tighten standards; many boilers will now emit no more than 0.60 pounds of particles per million BTUs of heat, down from about 1.2 pounds, said Lisa Rector, a senior policy analyst with the Northeast air-use management group.
In the meantime, smoke will continue to pour from heating units fueled by wood, whether it comes from outside the house or within, as at the 4,000-square-foot home of Jim Pasquale, a software executive in Warwick.
He has used a wood stove since 1993 in conjunction with an oil furnace. A more-efficient stove, bought in December, however, has allowed him to sharply scale back oil use, he said, from 12 gallons a day to 5 ¦, for a monthly savings of roughly $570.
"I'm reducing my dependency on fossil fuel," Mr. Pasquale said, "by getting back to basics."