Think of your home as one big refrigerator – would you put it in the shade or in the sun?  Of course you would put it in the shade.  Why?  Heat coming directly from the sun is radiant heat and radiant heat causes things to heat up.  This means the outside surface temperature of your refrigerator could easily be 130º in the sun.  So, the refrigerator “thinks” it’s actually 130º outside even though it is not.

Your roof acts the same way.  It can easily reach 150º or hotter on a sunny day.  This heat will then be re-radiated through the attic and will be absorbed by your attic insulation causing high energy bills and comfort issues.

This video illustrates how a radiant barrier works – plain and simple.  Rather than absorbing the radiant heat from the roof, let’s bounce it back and keep the attic insulation cooler. If you keep the insulation cooler, then less heat enters the home and you save money and stay more comfortable.

Think of it this way:  Radiant barrier is your 1st line of defense against radiant heat and your attic insulation is your 2nd line of defense against conductive heat.  They will actually work TOGETHER for maximum efficiency and comfort.

Looking for more videos on this topic? Check out my posts below.

  • The #1 Attic Ventilation Problem
  • Enerflex® Radiant Barrier at Home Depot compared to AtticFoil® Radiant Barrier
  • Radiant Barrier Installation Summary – Block the Heat
  • Green Energy Barrier (and other products) Compared To AtticFoil® Radiant Barrier Foil
  • Does Radiant Barrier Damage Roof Shingles?
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    8 Comments to “New Video=>SUMMER HEAT – It’s coming. What’s your defense?”

    1. Jessica says:

      We are looking to install a radiant barrier and have been told it’s best to install a solar powered fan as well. Is it necessesary to have both installed? Your blog is very helpful. Thank you.

      • Ed Fritz says:

        A radiant barrier will work ANYWHERE. Inside, outside you name it. Radiant barrier AtticFoil is usually installed INSIDE an attic as a retrofit application. Getting a radiant barrier to the outside of the structure is usually only available during new construction or if you are doing some type of “raised” roof that contains an air space. The perfect case would be to build your home like a well insulated, air tight refrigerator to reduce conductive heat and then wrap it with foil (even if it is behind brick, stone, siding, roofing etc.) as the first line of defense against radiant heat.

    2. Jim Shorr says:

      Should radiant barrier make contact with insulation at/near soffit areas….it seem it would create a heat sink, if so?
      Should baffles be installed in same area before barrier install?
      WHEN should addition of blown fiberglass be done…before/after radiant barrier. In my case present attic floor is approx R-16 and I would like to supplement (with blown fiberglass via contractor) to R30 or R-60 for my Atlanta, GA location?

      Thanks very much.

      Jim shorr

      • Ed Fritz says:

        Jim,

        If you are stapling up, it is very possible you will have some contact with the insulation near the soffits. If the contact is on the bottom only then there is no reduction in effectiveness. You should install the radiant barrier using the staple up method FIRST. You will probably compress and disturb your existing insulation somewhat during the installation – it’s part of the job. Then, blow in additional insulation and stay out of the attic.

    3. Kirk says:

      Ed,
      If applied to the rafters, would this create more heat for the shingles and lessen the lifespan of them?
      If applied to the ceiling joists, is there a possibility for condensation?
      Thanks!

    4. Sandy says:

      I am getting ready to reroof after hail storm. My house is c1920, has no overhand or soffits and only has one gable vent in the front. I want to install decking, new shingles and Attic Foil, but am perplexed on ventilation. Roofer suggests ridge vents, but the only air intake is the gable vent. What to do if there is no soffit? With Attic Foil and ridge vents will I be ok ventilation wise?

      • Ed Fritz says:

        Sandy, You have a unique situation that calls for a unique solution. Here is an idea. Install a solar vent, but REVERSE the wires to make the solar fan push air INTO the attic rather than pull it out. This is called “Positive Pressure Ventilation”. It’s not the most ideal setup, but it is a lot better than not having any intake (soffit) vents. You would put the fan as far away from the gable vent as possible. Air would be “Pushed” into the attic and would travel the path of least resistance to the gable vent. Once again, It is not the most ideal method, but I’ve seen it work very effectively on many homes.

        Another option is since you are getting a new roof, you can install an “edge vent” or there are also several brands of “ventilated fascia board”. Both these type products will ACT like soffit vents.

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