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What happens here?

Buildings, energy, energy policy, indoor air quality, problems, triumphs, successes, failures and the people and processes that affect them.

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Tuesday, March 12, 2013

Radiant barriers are seldom the cost effective option, especially in the north.

This is the current perversion of a bit of science into over enthusiastic marketing. Radiant barriers can, when properly installed, reduce radiant transfer of energy. The question is whether this is the best use of your home improvement budget. In my opinion the answer is almost always a resounding NO!

Before we go any further download this information from the Oak Ridge National Laboratory (ORNL) http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&ved=0CF0QFjAE&url=http%3A%2F%2Fwww.ornl.gov%2Fsci%2Fees%2Fetsd%2Fbtric%2FRadiantBarrier%2FRBFactSheet2010.pdf&ei=MIY3UdahKsSo0AGfnYAg&usg=AFQjCNHP3S7G_7P2KLEhesLTMuIOId31NA&bvm=bv.43287494,d.dmQ

This rather dull fact sheet lays out the case for and against the radiant barrier in different climates, with savings estimates for several starting points. In short it finds that even in warm climates radiant barriers are not always the cost effective solution. Cold weather climates really offer little opportunity for savings.

Have you ever been approached by a salesperson for this technology? What was your reaction to the pitch? Leave me a comment below.


  1. We have a stone house, circa 1734 in Pennsylvania and are perplexed about options for insulation. We also have very little money. We were going to look at a radiant barrier but were not sure how useful it would be. We opted not to get blown in insuation because of the concern for moisture buildup...what resources can help? John H

    1. John,

      Stone and brick construction can present some of the most difficult situations for retrofitting insulation. The best approaches from a building science perspective often hide the surfaces that make these homes so attractive.

      You're right to make moisture your 1st concern. That should be the #1 concern in every retrofit situation. As I often say, energy is easy, water is hard. Getting the details right is key to a successful energy improvement job.

      The best single source for this type of information on the web is http://www.buildingscience.com/index_html. The only downside is that the the amount of information can be overwhelming.

      There is a lot of, well, spurious, information out there so be careful. Probably the best advice I can give you is to get professional help :-)

      Seriously, find an independent building science consultant in your area. Someone who is not selling a product or system is going to be your best ally. The upfront cost is going to save you from making expensive mistakes. Look for someone with experience in your type of building and check references and, most importantly, make sure you are comfortable working with the person you engage.

      Your first sources could be the BPI web site, www.bpi.org, and RESNET, http://www.resnet.us/.

      This will ensure that the person has at least a foundation of building science education. Still, nothing trumps experience so look for someone who is especially sympathetic to the special circumstances of older homes.

      If you're patient I'm going to be writing about some approaches for energy saving in older homes as I have the time. Just remember that to you, I'm just another guy on the internet. Find someone who can look at your home and make good suggestions for you and your historic home.

      Good luck and let me know how you are progressing.