As Larry Stopa ate a free steak at an Oshkosh, Wis., restaurant, he listened to a sales pitch for "radiant barrier" insulation that was supposed to save him a bundle.

Stopa was skeptical of claims that a thin blanket of aluminum-clad insulation laid over existing attic insulation could significantly reduce heating and cooling costs.

Stopa later researched the product and concluded that the radiant barrier seller was "scamming the seniors," who made up the the majority of the audience that day.

The Minnesota Department of Commerce is concerned, as well. For the second time in as many years, the department has warned consumers to think twice about installing radiant barriers, because of their questionable benefit in northern climes.

"Radiant barriers in attics may be valid for homes in Southern states," said Commerce Commissioner Mike Rothman, "but they save very little energy in Minnesota homes."

A radiant barrier is basically a shiny aluminum foil that causes radiant heat to bounce off. Its close cousin, reflective insulation, is made up of a sheet of polyurethane foam or a Bubble Wrap-type of material sandwiched between aluminum. It's typically less than a half-inch thick.

While reflective insulation does has a small R-value, or ability to stop heated air from moving through it, radiant barriers have none, according to the U.S. Department of Energy.

Local energy providers are also unimpressed with the value of the products for cold-climate customers. Xcel Energy and CenterPoint Energy offer no rebates for installing the products in Minnesota homes.

"Neither product has sufficient R-value to qualify," according to Greg Olson, trade relations manager for Xcel.

"Generally, [radiant barriers] are the wrong tool for the job based on our climate and the construction techniques we typically see in Minnesota homes," said Rebecca Virden, spokeswoman for CenterPoint.

Radiant barriers and reflective insulation can produce decent reductions in cooling costs when used in warmer regions.

An Energy Department fact sheet states that if a consumer lives in the deep South and has ductwork in the attic, installing a radiant barrier could save as much as $150 per year.

"I believe in the technology," said Bill Lippy, president of Fi-Foil Company Inc.,a Florida business that manufactures radiant barriers and other products.

A committee Lippy chairs for the Reflective Insulation Manufacturers Association International is working on challenging "conservative" government estimates of energy savings, he said.

"There's companies out there, like anything, that oversell," Lippy said. "They give certain things a bad name, whether it's aluminum siding or whatever. They often prey on people's ignorance, and I think in this case, that's probably what happened, but that doesn't mean the technology doesn't work."

Company claims

A Better Business Bureau spokesman identified four installers that sell to Minnesota consumers. Whistleblower looked into claims made by the two companies located in the state, both with "A" ratings.

Grade A Contracting of Savage, which also does business as Midwest Energy Solutions, claims that its reflective insulation is a "product that will pay for itself over short time." Two phone messages seeking comment were not returned.

Using an Energy Department online calculator, a Minneapolis homeowner with attic ductwork could save up to $40 per year by attaching a radiant barrier to the rafters. But the company's website shows a horizontal application, which wouldn't cover the ductwork and which would become less effective over time as dust settles on it.

Most Minnesotans don't have ductwork in their attics, which causes savings to drop dramatically. Whistleblower put her home in the calculator and found she could realize a 20-year savings of $0. But adding a little more fiberglass insulation could save $140 a year.

The unnamed companies, which typically market their products over complimentary meals, are charging $2,000 or more to install their products, according to the Commerce Department. With a $20-per-year savings, it would take 100 years to break even. That's an expensive free dinner.

The company that Stopa said put on the presentation in Oshkosh, Innovative Energy Solutions of Edina, failed to return several phone calls from Whistleblower seeking comment.

BBB ratings

After Stopa researched radiant barriers, he filed complaints against Innovative with several Better Business Bureaus, including the BBB of Minnesota and North Dakota. "The IES salesman made a big point that the BBB rated Innovative Energy Solutions as an A," Stopa said. The complaint appeared to have no effect on the business' rating.

BBB ratings are based in part on how responsive companies are to complaints, according to Dan Hendrickson,spokesman for the BBB.

"Overall, [Innovative has] been responsive to our concerns" and recommendations, and, Hendrickson continued the relatively few customer complaints the BBB has received have been resolved.

In its response to Stopa's complaint to the BBB, Innovative said he was confused and that its product was different than what the Department of Commerce was warning about.

On Friday, the BBB put the company's rating on "update until they've addressed a couple of follow-up concerns regarding energy savings claims on their website," Hendrickson said.

Stopa, a business owner, said that he won't be renewing his membership in the BBB of Wisconsin because he now considers its rating system meaningless.

To calculate how much you could save by having a radiant barrier installed, go to www.startribune.com/a2213.

Jane Friedmann • 612-673-7852