The Rumford fireplace - energy-efficiency rediscovered
In the 1800s, a Rumford fireplace was the latest word in energy efficiency. They're still being built.
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The This Old House website has a quick primer on what makes a Rumford different:Skip to next paragraph
Alexandra writes about the "green" and budget-friendly renovation of a 100-year-old farmhouse in south-central Connecticut.
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In a traditional fireplace, the fireback slopes forward to direct smoke up the chimney. Incoming air spills over the sharp edge of a steel lintel eight or nine inches below the damper, mixes turbulently with the smoke and "rolls" upward. While this construction prevents the fireplace from smoking, it also loses some of the fire's heat up the chimney.
Count Rumford designed a fireplace with a high, wide opening, a shallow firebox and widely splayed jambs to reflect as much radiant heat out into the room as possible. But Rumford's real genius was straightening the fireback and rounding the front wall of the throat, essentially creating a nozzle—like an inverted carburetor—that shoots smoke up through the damper and out the chimney, wasting less heat in the process.
So I asked our local mason, Louis “Gino” Spada, if he could build us a Rumford. He said he could, it would just cost a bit more. Again, we find ourselves paying more now to save later. But it was only a few hundred dollars, so we decided it was worth it.
But one thing stumped me: If these fireplaces were so efficient why haven’t they been standard since the 1800s when they were so popular?
I couldn’t find any simple explanation – except maybe that frugal Americans ended up being penny-wise and pound foolish (or “fuelish,” as it were. Forgive me, I couldn’t help it.)
Gino, who builds about a hundred fireplaces a year, says that at most, he might build two to three Rumfords annually. He thinks it’s because people are less concerned about using a fireplace for heat than they once were.
“People don’t use fireplaces as much for heat; they use it for looks,” he says. “It’s a pity, people want what they want. Rumford’s a good fireplace.”
It turns out that the count also invented a cast-iron stove that “competed successfully with the famous Benjamin Franklin stove. Both devices gave much more control over the air flow into the fire, and were both much more efficient users of fuel. Such stoves were expensive, but saved so much fuel as to justify the cost of installation very quickly.”
So here’s to rediscovering American ingenuity. If you want to find out more about the count and his fireplaces, his birthplace has been converted into a museum.
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Editor’s note: Alexandra Marks blogs on Tuesdays and Thursdays about her green and budget-friendly restoration of a 1902 farmhouse in Connecticut.