Harvesting free heat from the sun
By Melanie Savage
Columbia - posted Mon., Feb. 7, 2011
It’s eleven o’clock in the morning, and a cozy 70 degrees in the Columbia kitchen of Judy Senkbeil. Outside the snow is piled three feet high, and the yard is a sheet of ice nearly a half inch thick. “I fired up the wood stove to cook breakfast,” said Senkbeil, “but then I let it go out.” Because it is sunny outside, the stove will stay dark for most of the day. “The house usually stays warm until supper time,” she said, “and then I start up the wood stove.”
The secret is the solar hot air system that Senkbeil had installed last April. For a total of about $2,100 for supplies and installation, the system has freed her from wood stove duties during daylight hours on most days. Because Connecticut has had an unusually stormy January, there have been some days when the unit has not kicked on. “This winter it’s probably been on a bit over half of the time,” said Senkbeil. But when it does run, the hot air system moves the home one step further away from a reliance upon fossil fuels.
The household has used solar hot water since 1972, and is heated primarily by wood stove. There is an oil-burning furnace, but that is only used on occasion. Compostable trash is recycled via chickens and other livestock. “I was born a Scotsman, raised with Yankees and Jews, and married a German,” said Senkbeil. “I’m as frugal as they come.”
Senkbeil stumbled upon solar hot air while researching solar electric. According to a solar supplier in Vermont, “this was much cheaper than solar electric, and more efficient,” said Senkbeil. She estimates a four-year payback “depending on the price of oil.” The system will save money, reduce the home’s carbon footprint, reduce its dependence on foreign energy sources, and reduce Senkbeil’s work load. “It’s a really great choice for a lot of different reasons,” she said.
Senkbeil’s home is approximately 1,400 square feet, and requires two large solar collection panels. For maximum efficiency, panels should be mounted in a southern exposure. Senkbeil mounted hers on the side of the house, but there are systems that allow for roof or even ground mounting. In a closed loop system such as Senkbeil’s, cool air is drawn from the home via a five-inch fan, circulated through the panels, and returned to the home through a four-inch vent. Senkbeil has two of these setups, one on the first floor, one on the second. Installation is fairly easy, consisting of mounting the panels and installing the vents. There is some minor electric work involved, although some kits even come with a solar-powered thermostat, so the system still runs during a power outage.
For an in-depth look at the variety of solar hot-air systems available, go to www.motherearthnews.com. Senkbeil ordered her system through a company called Clear Dome Solar out of California (cleardomesolar.com), but there are numerous suppliers nationwide. “I hope to be able to help people save a whole lot of money,” said Senkbeil.