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

Question

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

Asked by jerry h.

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.

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Answers

Danny Kelly's picture

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.