The New York Times
March 28, 2008
DINING beside the patio fireplace in Maine in April. Swimming in the backyard pool in Arizona late into a cold March night. Nightcaps around the outdoor fire pit in South Carolina in November.
Whether it’s extending the short summers of New England or delaying the onset of a chilly desert night, second-home owners are extending their time outdoors by, well, heating the outdoors. Surprisingly, it’s not terribly expensive, but it can be costly to the environment.
Among the cheapest and most environmentally friendly outdoor heat sources are freestanding and tabletop propane heaters, which start as low as $50 but are usually $125 to $400. They usually use less gas than a barbecue grill.
Built-in gas-fueled fire pits range from a few hundred dollars to several thousand, depending on the size, fuel and design. Propane and natural gas flames emit carbon dioxide and other greenhouse gases, but they do not produce the fine particulate pollution associated with wood fires.
Portable wood-burning fire pits, essentially metal bowls with grates, usually start around $110. The wood is a renewable resource, of course, but an evening’s fire can send a pound of dagger-shaped fine particulate pollution into the air, according to Mary Rozenberg, president of Clean Air Revival, a nonprofit organization that campaigns for the reduction of particulate pollution. Its Web site, www.burningissues.org, is a guide to scientific studies of smoke in the atmosphere.
Outdoor fireplaces are considerably more expensive; the sky’s the limit if your taste runs toward things that resemble Tuscan castles. They’re often used the way indoor fireplaces are, to create an ambience while most of the heat goes up the chimney.
Some manufacturers offer prefabricated fireboxes and flues for outdoor wood-burning fireplaces that send more radiant heat out onto the patio, and some claim their products burn so efficiently that particulate pollution is reduced, a claim that Ms. Rozenberg dismisses. Manufacturers also offer gas versions.
The Hearth, Patio and Barbecue Association, a trade organization based in Arlington, Va., reports that at least 600,000 outdoor fireplaces and fire pits — only about 12,000 of them gas — were sold in 2006. “That’s a conservative number,” said Don Johnson, director of market research for the association, “because some big retailers don’t share sales information.” (That figure also doesn’t include 157,500 propane patio heaters sold in 2006 by specialty retailers.)
He added that his group is working with the Environmental Protection Agency and manufacturers to reduce particulate pollution, especially from wood-burning stoves. “Outdoor fire pits and fireplaces are not a big part of the problem,” he said, “because they’re used so little.”
Ms. Rozenberg, however, objects even to occasional backyard fires.
“When people light leisure fires, they are contributing to the ill health of someone else,” she said. “There is no protection from fine particulates, which stay in the air for weeks and are laced with toxins.”
The effects of wood smoke are not a factor when it comes to warming the most expensive backyard amenity. To get the maximum use of their swimming pools, many second-home owners heat them. A gas-fueled heating unit can, depending on the size of the pool and the climate, cost as little as $600 or as much as $2,000 or more. The propane or natural gas to power the heater can easily run $300 to $600 a month.
A heating unit used in conjunction with a solar cover, which floats on the water and curtails heat loss by blocking evaporation when the pool is not being used, can keep you and your guests doing laps well into the cooler months. Solar covers also help heat the water by magnifying the heating effect of sunshine.
One pool installer in Arkansas — who would not speak for attribution for obvious reasons — argues against installing heaters, at least where the heat isn’t needed June through August.
“People will pay for the heater, then see their gas or fuel oil bill go up $300 a month or so,” he said, “and then they realize that the kids are in school in May and September. They put all this money into heating the pool, and nobody’s using it.”
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