Finnish-made Tulikivi thermal-mass fireplaces are pricey, but they burn cleanly and their soapstone surrounds generate warmth for up to 24 hours after the flames have dimmed.
The fireplace has long been an iconic symbol in American culture. “It takes us back to grandmother's house,” says Carbondale, Colo.-based architect Doug Graybeal, AIA, “and it's better than television.” But, setting aside our affinity for nostalgia, grandma's house was woefully short on energy efficiency, and her fireplace was a major source of the problem.
Today's higher standards for sustainability and energy efficiency are putting that much-loved hearth in a compromising position. “Fireplaces have a high aesthetic value, but they have a low environmental efficiency value,” says Rick Harlan Schneider, AIA, principal, Inscape Studio, Washington, D.C. “They're often more trouble than they're worth.”Fireside Chat
According to the California Environmental Protection Agency's Air Resources Board, most wood-burning fireplaces rob houses of heat because they draw air from the room and send it up the chimney. Along with their inefficiency, fireplaces contribute to indoor and outdoor air pollution. In 2004, the American Lung Association of California called wood smoke from fireplaces “the largest stationary source of air pollution in the Bay Area during [the] winter months.”
That's not to say that fireplaces have fallen out of favor with architects. Indeed, they're as popular as ever. Graybeal is a huge fan—especially of efficient, heat-producing Rumford models—and Harlan Schneider still specifies them in his work. “In one project, we designed a fireplace for aesthetic value, but the chimney was designed to be a thermal mass,” he says.
As Graybeal and Harlan Schneider's experiences demonstrate, fireplace-favoring architects concerned with energy efficiency do have options. Hearth & Home Technologies, Travis Industries, Lennox Hearth Products, and other manufacturers have developed a large and varied line of eco-friendly hearth products that offer the aesthetics of fire—and some of the warmth that goes with it.
Pellet stoves, for example, are among the cleanest-burning hearth products on the market. Available in freestanding or built-in models, these stoves burn biomass pellets made from recycled wood waste. “Pellet stoves are very efficient,” says John Crouch, director of public affairs in the Citrus Heights, Calif., office of the Hearth, Patio & Barbecue Association (HPBA). “The key to the system is that it burns a small internal fire.” Pellet stoves also provide a fair amount of heat—anywhere from 25,000 BTUs to 60,000 BTUs per hour, Crouch says. Some even use clean-burning corn kernels and don't require a conventional chimney.
An EPA-approved wood-burning stove is another excellent alternative. According to the agency's Web site, EPA-certified wood stoves burn more efficiently than older, noncertified models because significantly less creosote builds up in their chimneys. EPA-certified stoves perform a slow, controlled burn by limiting the amount of combustion air, resulting in an air-to-fuel ratio of about 15:1. (By comparison, open wood-burning fireplaces typically have an air-to-fuel ratio of more than 50:1.) According to HPBA, wood stoves are excellent heat sources because they operate at rates of up to 70,000 BTUs per hour.
“Before I got into doing green houses, I loved fireplaces, because they are a very sculptural element in a room,” says Paula Baker-Laporte, an architect and author on sustainable design practices based in Tesuque, N.M. Then she discovered more eco-friendly options, including Tulikivi fireplaces. According to their Finland-based manufacturer, Tulikivi thermal-mass fireplaces store large amounts of heat because they're made mostly of soapstone. They also burn wood so cleanly that they even outdo the strictest environmental codes. Baker-Laporte says she sometimes uses a mason to build a custom thermal-mass fireplace, but she'll substitute certified wood stoves when the budget is tight.
The environmentally friendly EcoSmart fireplace burns byproducts of sugar cane and other biodegradable items. The self-contained units require no fuel line or flue, but need a room dimension of at least 2,400 cubic feet for adequate ventilation.