Tuesday, July 26, 2011

Taking Energy Efficiency to the Next Level: Furnace-less Homes!

Want to save a bunch on heating and cooling costs in a home, even in cold climates? Build the house without a furnace. It’s possible now, and a the Cleveland Museum of Natural History has just built one. In fact, thousands of furnace-free homes have already been built in Germany, but only 15 U.S. buildings have this same level of extremely low energy use.

The house in Cleveland has walls that are more than a foot thick, big triple-pane windows, doors that resemble bank vaults and engineering that cuts heating and cooling costs, as well as pollution, by 90 percent.

These futuristic dwellings are known as “passive houses”, and cost about 20 percent more than conventional housing to build. The museum decided to give its visitors a look at what the future may hold as energy costs skyrocket.

“We have to get beyond incremental improvements to get a dramatic breakthrough,” said David Beach, the museum’s director of sound urban practices. This houses, he said, is “an example of a new way of living.”

Special Insulation is the Key

The house has an insulation system with a sealed air barrier that makes it work like a thermos. A ventilator exchanges the heat from the stale, outgoing air with the fresh incoming air, allowing very little heat to be lost. Two ductless heat pumps, one upstairs and one down, supply all the heating and cooling necessary no matter how hot or cold the outside air is.

The doors are extremely think to insulate well.
The house features huge south-facing windows which allow maximum solar heat in winter, when the sun is low in the sky. A ridge over the windows blocks much of the sunlight in the summer months, when the sun is higher in the sky.

Cleveland endures some of the harshest winters in the U.S., so if this house can achieve certification here, chances are it can do it anywhere.

A certified passive house must meet the same stringent energy-saving standards as in Germany. To qualify, a house must meet or beat 80 to 90 percent reduction of heat-trapping gases, the amount needed by mid-century to avoid creating dangerous climate shifts.

Return on Investment

The Department of Energy estimates it costs more than $900 a year to heat and cool an average house in the Ohio area. A passive house is approximately 15 percent more energy efficient than homes built to code. The cost of building a passive house is about $10,000 more, so the point at which the extra cost is offset by the energy cost savings is about 10-11 years. Of course, as energy prices increase, the efficiency of passive homes will make it pay off in even less time.

Source: Renee Schoof, McClatchy Newspapers