Why is "reflective insulation" still being sold by HD and Lowes -- and used by many contractors?
I stopped by my local HD for more supplies and was surprised to see rolls of "radiant barrier" bubble wrap on the shelf. Lowes and online vendors sell products with similar claims. For example, here are the benefits promised by a leading vendor:
"An easy-to-install double reflective, double bubble insulation
R-values range from R-3.7 to R-21 depending on the applications
Energy-saving residential applications include: cathedral ceiling, crawl space, radiant floor,
wall, HVAC duct, water pipe, garage door, knee wall..."
R 21 ?? !! As GBA articles and posts note, the typical claims for radiant insulation are snake oil, put to the lie by 20 years of independent studies, FTC and Attorney General actions etc.
Unfortunately, builders, contractors and customers continue to fall for these claims. For example, the HVAC contractor at our latest project showed up with a big roll of Reflectix and began to wrap the plenums. The label on the Reflectix roll boldly claimed "R6", with a small note that R4.2 was the expected level of insulation with HVAC ducts. if you read the excellent reviews and commentary on GBA, you know you should read this fine print very carefully. R4.2 is only achievable with a perfect assembly, a consistent air space and horizontal orientation -- and no dust on the foil surface.
These claims are not unique; launch a Google search for "reflective \ insulation" and see how many products and extravagent claims appear in your browser.
This is a whack-a-mole problem. When one vendor is hit by the FTC or an AG suit, another pops up. "Reflective insulation" is very cheap to manufacture, so new products quickly appear with more wild claims.
It is past time, well past, for professional builder organizations to join together nationwide -- and put an end to this charade.
Included below are links to a number of reputable sites and independent studies:
Healthy Heating: 20 years of research studies on reflective 'insulation':
(Scroll down to see the newer studies)
GBA: Is Bubble Wrap Duct Insulation a Good Idea?
Energy Vanguard: The Foil Faced Bubble Wrap Sham
GBA: A great collection of all of the questions and claims for HVAC installers:
A copy of a thorough 2010 study by the Canadian National Institute for Research in Construction is also attached. Their conclusion: In a perfect state (with no dust on the surface), a radiant barrier with an air gap increased the efficiency of insulation in a wall by 10%. In other words, if the wall was already R6, adding 'miraculous' foil bubble wrap added .6, for a total of R6.6.
|Canada - IRC study of reflective insulation - 2010.pdf||450.84 KB|
Posted Fri, 12/06/2013 - 22:59
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