The Well-Designed Building Envelope
March 10, 2010 by eralls
Filed under Insulation Facts & Advice
When it comes to designing your home, “the greenest thing you can do,” according to Residential Design & Build magazine, is to “design a high-integrity thermal envelope so your structure consumes as little fuel as possible for heating and cooling.” Sure, VOC’s, recycling and hybrids are also important to living a sustainable lifestyle, but greening the building shell should be your No. 1 priority.
So where to begin? Start by using non-toxic, sustainably harvested materials that don’t consume a great deal of fuel when ship. This includes roofing, air filtration, insulation, adhesives, caulks, sealants, wood and more.
And when it comes to insulation, Henges has you covered. Because, as RB&D reiterates, “Cooling U.S. homes costs $40 billion yearly and consumes 15 percent of all U.S. power, 90 percent of which is created with coal and fossil fuels. Proper insulation can easily save 20 percent of fuel costs. There are intriguing choices out there that go way beyond standard batts, such as insulation with “smart paper” facing that changes its molecular configuration to allow moisture in or out. But for all insulation, consider formaldehyde, a known carcinogen that is widely used in binders and adhesives. Also, look for low-emitting or formaldehyde-free products. For filling gaps, use spot-application spray foams that are isocyanate-free and formaldehyde-free.”
Read more on “Greening the Building Shell.”
The formaldehyde free insulation is a critical issue for the wall. Many consumers incorrectly think that formaldehyde generated in wall gavities doesn’t make it into the interior air. I was invited down to a Southern CA subdivision where the indoor formaldehyde was up to 75 ppb. That is 10 times the current recommendation made by the State of CA. The single biggest contributor appeared to be the wall insulation.
As the building shells have become increasing tight for energy conservation, it has become critical to properly ventilate homes. We learned this on commercial buildings in the late 70’s early 80’s and currently require a complete air exchange per hour. Homes have far more sources of pollution yet were have just started requiring one air exchange every three hours. It should be more not less.
People wonder why childern are sicker since double pane windows were required. The answer is simple the air exchange rate was decreased (good for energy conservation) but very bad for the occupancts health. Impacting those that spend the most time at home (children) and those that have the least body mass (children and women) and those with the highest ventilation rates (children).
Hello, does anyone see the perfect storm we have created? If not read the California Air Resources Board December 15, 2009 abstract which among other things states:
“Nearly all homes (98%) had formaldehyde concentrations that exceeded guidelines for cancer and chronic irritation…”