©2015 Green Building Advisor. From The Taunton Press, Inc., publisher of Fine Homebuilding Magazine.
Scammers have been selling “insulating” paint to gullible consumers for at least 27 years. Among the exaggerated claims made by distributors of these overpriced cans of paint is that the “low-e” coatings will “lower energy bills.” In addition to liquid paint, some fraudsters sell powders or paint additives, usually described as “miracle” products containing “micro-spheres” or “ceramic beads.”
Every few years, the sleepy regulators at the Federal Trade Commission (FTC) wake up long enough to send warning letters to the most egregious paint scammers. For example, in 2002 the FTC clamped down  on Kryton Coatings International, a manufacturer which claimed that its paint was equivalent to 7 in. of fiberglass insulation. In March 2009, the FTC took action  against Sumpolec, a marketer of coatings that were said to “equal R-100 insulating value.”
To find them, just lift a few rocks
In spite of these rare actions, however, marketers of “insulating” paint continue to thrive. With a simple Google search, any Web surfer can conjure up dozens of distributors of insulating paint, including those hawking Nansulate and Super ThermUnit of heat equal to 100,000 British thermal units (Btus); commonly used for natural gas..
When I was the editor of Energy Design Update (EDU) — a position I held before joining the GBAGreenBuildingAdvisor.com team in November 2007 — I regularly exposed exaggerated energy claims made by paint manufacturers. My March 2004 article, “R-Value Scofflaws,” fingered the manufacturer of Super Therm. In June 2008, I wrote “Scam and Exaggeration Roundup,” an article highlighting exaggerations made by Nansulate. Although both articles were forwarded to the FTC, the agency has so far failed to act against either manufacturer.
“A barrier to heat transfer”
The manufacturer of Nansulate — Industrial Nanotech of Naples, Florida —describes its flagship coating as a “liquid applied home insulation.” The company’s Web site  falsely claims that “Nansulate is a new technology which insulates by means of low thermal conductionMovement of heat through a material as kinetic energy is transferred from molecule to molecule; the handle of an iron skillet on the stove gets hot due to heat conduction. R-value is a measure of resistance to conductive heat flow.. … Residential customers typically report energy savings in the 20% to 40% range, which is of course dependent on each individual application. … You can boost the energy efficiency of your home by applying Nansulate to the interior walls, ceiling, and attic area. Nansulate will act as a barrier to all three methods of heat transfer — convective, conductive, and radiant. Radiant heat transfer is one of the most significant ways that heat is lost or gained from a home or building. Nansulate can be used as attic insulation, pipe insulation, wall insulation, and duct insulation in your home, helping you lower fuel bills.”
“R-19 equivalent insulator!”
If anything, the claims made for Super Therm are even more outlandish than those made for Nansulate. One Super Therm distributor, Eagle Specialized Coatings  of Surrey, British Columbia, advertises that “Super Therm is a true ‘insulating’ coating and not just a reflective paint as are all the competing formulas in the market. Also tested by the Thermo Physical Research Laboratory for comparative R-19 equivalent insulation factor Super Therm blocked 92% of the heat. No other R-19 equivalent insulator can claim that! No Fiberglass, No Foam, No Cellulose, No other single ceramic paint!”
The manufacturer of Super Therm, Superior Products International  of Shawnee, Kansas, claims that “Super Therm is a ceramic based, water-borne, insulating coating, designed to block heat load, moisture penetration, and air infiltration over a surface and to reduce energy costs. … Super Therm can provide energy savings of 20-70%. According to use and application. R-19 Equivalent Rating — Super Therm reflects over 95% of radiation from the sun replacing the 6 to 8 inches of traditional insulation to block initial heat load.”
How can these paint manufacturers get away with such wild exaggerations? Although the problem is due in part to the FTC’s lax enforcement of existing regulations, other factors play a role. According to an article in the September 2009 issue of EDU, “Such claims, as a rule, receive relatively little attention from energy experts. That’s partly because they are numerous enough that any attempt to debunk them individually would quickly develop into an open-ended game of Whack-a-Mole, and partly because the product claims are so outlandish that it’s difficult to imagine anyone taking them seriously.”
The same as ordinary paint
Every researcher who has examined these products has concluded that there is no such thing as insulating paint. For example, tests at the Florida Solar Energy Center  confirm that these paints are nothing special: “The Florida Solar Energy Center has tested ceramic paints and found them to have no significant advantage over ordinary paint in terms of their ability to retard heat gains through exterior building surfaces.”
The latest research lab to shine light on the insulating paint scammers is the Cold Climate Housing Research Center (CCHRC) in Fairbanks, Alaska. As explained in the September 2009 issue of EDU, CCHRC researchers decided to focus on two products that often generate customer complaints: Nansulate and Super Therm.
Are they low-e?
In theory, the lower the emittance (emissivityAmount of heat radiation emitted from a particular body or material. Emissivity is expressed in a fraction or ratio, with the lowest values indicating low emissivity and the highest indicating the high emissivity of flat black surfaces.) achieved by a paint, the better its performance. When CCHRC researchers tested the emittance of dried samples of Nansulate and Super Therm, however, they discovered that neither coating is low-e. An independent laboratory “tested the emittance of the coatings on three different samples for each coating. Super Therm had an average emittance of 0.9 and Nansulate had an average emittance of 0.92, which demonstrates that neither product is a good inhibitor of infrared radiant heat loss.”
The measured emittance values of these paints are truly dismal — far higher than the legal maximum for a radiant barrier, which is 0.10. (As it turns out, no paint on the market can meet the radiant barrier standard.) Some paint manufacturers classify their products as “radiation control coatings,” a category requiring an emissivity rating of 0.25 or less — a less stringent emissivity rating than radiant barriers. However, neither Nansulate nor Super Therm comes anywhere close to even this less stringent standard.
In any case, the emittance of residential paint is a moot point. A low-e coatingVery thin metallic coating on glass or plastic window glazing that reduces heat loss through the window; the coating emits less radiant energy (heat radiation), which makes it, in effect, reflective to that heat; boosts a window’s R-value and reduces its U-factor. is only effective if there is a large temperature difference between the surface being coated and the environment it faces. Such a large temperature difference can only occur on an uninsulated wall — and if your house has uninsulated walls, you have far more problems than can be solved by a few cans of paint.
Can paint have an R-Value?
In order to leave no stone unturned, the Alaska researchers measured the R-value of dried paint samples. Employing a Fox 314 heat flow meter, the researchers followed the standard ASTMAmerican Society for Testing and Materials. Not-for-profit international standards organization that provides a forum for the development and publication of voluntary technical standards for materials, products, systems, and services. Originally the American Society for Testing and Materials. C518 procedure for measuring R-value. (For more information on the ASTM C518 test, see “Understanding R-Value.” ) Since a thin coat of dried paint is fragile, the paint was applied to 1/2-in. drywall before testing.
The results will undoubtedly disappoint the marketers of “insulating” paint. “Application of Super Therm increased the thermal conductivity of the gypsum board and therefore decreased the overall R-value,” the researchers reported. “Application of Nansulate resulted in no signiﬁcant difference, as the change in thermal conductivity for the Nansulate-coated gypsum board is within the 1% measurement error of the Fox 314.”
If a tree falls in the forest …
Of course, R-value results are often ridiculed by those selling “alternative” insulation products. As Jon Vara, the current editor of EDU, recently explained, “Manufacturers of insulating paints typically claim that, although their performance can’t be quantified by some standardized tests, they are effective in the real world. A possible explanation: they only insulate when no one is looking.”
In order to test this unlikely possibility, the Alaska researchers built three insulated test boxes lined with drywall. The drywall in the control box was painted with ordinary latex paint, while the two test boxes were painted with Nansulate and Super Therm. “The boxes were placed outside and the heaters operated overnight maintaining the inside temperature at an average of 74°F,” the researchers reported. “Data were not collected during the day to avoid interference from solar heat gain. This control testing was conducted over the course of a week to ascertain that the boxes required the same amount of energy to maintain temperature. … Following the painting, all three boxes were set up with the sensors and heaters just as they were in the control tests, and tested outside overnight once every two weeks for a 30-day period.”
“No discernible difference”
Guess what — paint is a lousy insulator. The CCHRC researchers concluded that “there was no discernible difference in the performance of the Super Therm or Nansulate in comparison to regular latex paint during the energy monitoring tests.”
The ball is now in the FTC’s court. Anyone who wants to give the FTC a nudge should contact Hampton Newsome, the FTC attorney who handles enforcement of the R-Value Rule. Newsome can be reached by phone at 202-326-2889; his e-mail address is firstname.lastname@example.org .
The full CCHRC research report, “Product Test: Nansulate and Super Therm,”  is available online.
This article has been translated into Hungarian: A hőszigetelő festékek kereskedői becsapják a rászedhető lakástulajdonosokat .
Last week’s blog: “The Jevons Paradox.”