The Rumford fireplace - energy-efficiency rediscovered
In the 1800s, a Rumford fireplace was the latest word in energy efficiency. They're still being built.
One of the great pleasures of renovating Sheepdog Hollow in a green and economical manner is what one stumbles across while researching the best options.
I confess I didn’t exactly stumble on the Rumford fireplace. It was brought to my attention by Dale King, a builder we’re using who specializes in old homes. One day I was chatting with Dale and bemoaning the fact that fireplaces are so inefficient in terms of energy, and yet, so necessary -- at least as far as I’m concerned -- in a home – old or new.
“Have you thought of a Rumford?” he asked.
“A Rumford. They’ve been around since the 1800s. They’re amazingly efficient.”
And so I set out to discover just what “a Rumford” is. It turns out concerns about energy efficiency have been around a lot longer than the energy crisis of the 1970s and today's energy concerns.
In the 1700s, the cost of fuel (wood in those days) and how inefficient it was as a heat source also concerned great men. That’s what prompted Ben Franklin to invent the Franklin Stove in 1742. It’s also one of things that preoccupied a Woburn, Mass.-born physicist named Benjamin Thomson, who later became known as Count Rumford and for whom the fireplace is named.
Count Rumford, for whom the fireplace is named, was born Benjamin Thompson in Woburn, Massachusetts in 1753 and, because he was a loyalist, he left (abruptly) with the British in 1776. He spent much of his life as an employee of the Bavarian government where he received his title, "Count of the Holy Roman Empire." Rumford is known primarily for the work he did on the nature of heat.
Rumford fireplaces were common from 1796, when Count Rumford first wrote about them, until about 1850. Jefferson had them built at Monticello, and Thoreau listed them among the modern conveniences that everyone took for granted. There are still many original Rumford fireplaces -- often buried behind newer renovations --throughout the country.
Ah, American ingenuity and how quickly we forget it.
The This Old House website has a quick primer on what makes a Rumford different:
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.
Next: Not sure…!
Editor’s note: Alexandra Marks blogs on Tuesdays and Thursdays about her green and budget-friendly restoration of a 1902 farmhouse in Connecticut.