Question

What do you think of insulating paints that claim to lower your heating/cooling bill?

Asked by jerry h.
Hopkins, SC

Is this stuff legit? I am considering using it in my garage, which sits under our bedroom, to help keep our bedroom floors from getting chilly.

Answer

Danny Kelly

Answered by Danny Kelly

Charlotte, NC

Kelly McArdle Construction

February 22, 2011

Insulating paints -- often referred to as radiant barrier paints -- typically do not perform as promised.

  • A radiant barrier is defined as a product with an emissivity of .1 -- there is no paint on the market that meets this requirement.
  • I could not find anywhere in the literature where it states the actual rating of the product.
  • Closest I could find is .75, which is not a very good rating.

If you apply this product on the bottom of your roof sheathing, would it keep your attic cooler on a hot summer day? Probably a little, but not much. Using it in your garage will probably not get the results you are looking for.

A radiant barrier will not help with conduction and convection loss

Even if it did as it promised and reflected the heat, this only applies to radiant heat.

  • In your bedroom, you are more than likely losing the majority of your heat through conduction and convection -- a radiant barrier will not help resist the heat transfer of either of these.
  • You are better off air sealing and insulating at your floor.

If the budget allows, installing a rigid foam under your bedroom will help the performance tremendously.

 

For more information:

Read "Is a garage door insulation kit worth the time and money? Will the insulation make a difference in temperature for a room above it?" a Q&A answered by Lee Hall.

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