Your home's hidden environmental horrors
by Jonathan Fahey, Forbes.com
Monday, June 14, 2010
There's not a wind, breeze or draft that can't be stopped by Tedd Bensonwood, a builder based in New Hampshire who specializes in energy-efficient homes.
Until recently, one way he would keep out the chilly New England air was by wrapping houses with 4-inch-thick extruded polystyrene, an insulation sold under brand names like Dow Chemical, Styrofoam and Owens Corning Foamular.
It turns out, though, that these materials contain a particular type of hydrofluorocarbon that happens to be 1,430 times more potent a greenhouse gas than carbon dioxide.
It would take 65 years of greenhouse gases saved by this insulation to offset the damage done by this hydrofluorocarbon, according to Alex Wilson, author of the book Your Green Home and founder of BuildingGreen, an organization that provides green design information.
"A lot of people that care a lot of about the environment are using a lot of insulation in their buildings, for the right reasons," says Wilson. "But by using a couple of types of insulation, they are defeating their efforts."
Says Bensonwood, who no longer uses the insulation, "It's very frustrating; we're trying to save energy."
Owens Corning says its own analysis of XPS insulation, reviewed by outside experts, shows its global warming impact is “an order of magnitude” less than what Wilson’s study concludes. Dow says its newest technology uses less hydrofluorocarbons than Wilson assumed, and that an outside sustainability firm rated its XPS insulation highly. Neither company makes its exact formulations public.
There are all kinds of appliances and materials used to power, entertain, heat, cool, build and beautify our homes that use up resources in ways that are obvious, hidden or hidden in plain sight.
For example: You thought your gas range was just using gas to bake your cookies? Not so. Most gas ranges use electricity to power what's called a "glowbar" that helps govern the gas valves. These can draw 500 watts of power, almost as much as the microwave oven you were proud of yourself for not using.
Many things in your home, from your plasma television to your simple little toaster, draw power all day and all night just by being plugged in. According to researchers at Lawrence Berkeley National Laboratory, a typical American home has 40 appliances drawing power 'round the clock. Together they consume 10% of residential electricity use nationwide.
That 700-pound granite countertop? Even if it is mined locally, it is often shipped elsewhere to be cut and polished, then it's shipped back--burning fuel going to and fro.
Nate Kredich, vice president for residential market development at the U.S. Green Building Council, says what is needed, but difficult to get, are life cycle analyses of products' impacts that factors in production, transportation, the sources of the raw materials and how long the product last.
This last question, longevity, makes the calculation especially tricky. For all the energy it takes to produce granite, it can last a very long time. "If something lasts for 100 years and doesn't have to be replaced, that can be very green," Kredich says. "The whole thing is a trade-off. There are no easy answers."
Thankfully, though, says BuildingGreen's Wilson, there are often clearly preferable options. Substituting extruded polystyrene with insulation made with polyisocyanurate reduces the greenhouse gas payback from 65 years to just 2.7 years. Now that's green.
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In Pictures: 10 Environmental Horrors In Your Home