Save up to 40% on your home's utility costs with Radiant Barrier
What is Radiant Barrier?
Radiant Barrier is used primarily in residential construction to stop summer heat gain and winter heat loss. By installing this in your attic, you can reduce summer heat gain and winter heat loss by as much as 97%.
How does Radiant Barrier work?
Radiant heat, the major source of heat flow, is energy in the form of infrared waves. It is transmitted from a heat source -- like the sun, a heater, or even your body -- at the speed of light, through the air. This means that in your house, up to 90% of summer heat gain, and up to 75% of winter heat loss, comes from "Radiant" heat.
Unfortunately, typical bulk insulation (like foam and fiberglass), are designed to work against Conductive Heat (heat by physical contact) and Convective Heat (forced air). They are just not designed to work against the biggest perpetrator of heat gain and loss.
Just remember that up to 90% of summer heat gain and up to 75% of winter heat loss comes from Radiant heat. Bulk insulation can't stop radiant heat -- 90% of that heat actually gets through it.
Radiant Barrier works by reflecting radiant heat back toward the heat source -- it's like covering hot food with aluminum foil to keep it warm. In fact, Radiant Barrier is made from aluminum, so it's 97% reflective. That is, 97% of all radiant heat that hits it is reflected back toward its source.
What is the R-Value of Radiant Barrier?
Because it is a Radiant Barrier, rather than a reflective insulation, it doesn't have an R-Value. In addition, R-Value is a misleading number. R-Value only measures Conductive Heat (heat by physical contact). And since 90% of all summer heat gain and 75% of all winter heat loss comes from Radiant Heat, R-Value is not actually a valid measurement of performance.
Compare reflective insulation to fiberglass:

Notice how the temperature underneath the reflective insulation is 59 degrees fahrenheit cooler than the temperature under just six inches of fiberglass. The fiberglass has the much higher R-Value, but it's not doing more -- in fact, it's costing you money in increased utility costs.
This does not mean that you should use only Radiant Barrier in your home. We strongly recommend that you use bulk insulation in your attic and walls -- it helps with air infiltration and helps prevent condensation, which are two other causes of high utility bills. That, and building inspectors require it.
What does that mean?
It means that in the typical attic, there is anywhere from 1" to 12" of some kind of bulk insulation (foam, fiberglass, cellulose, rock wool, etc). However, when the attic fills up with summer heat, that bulk insulation is only stopping a small fraction of the Radiant Heat (10 - 20%). The rest of that heat is going into your house, which means the air conditioner runs continually to keep up with the constant heat flow.
But by laying Radiant Barrier on the attic floor, or stapling it across the roof rafters, you can stop that incoming heat, which means you'll reduce the amount of time your air conditioner runs. Which means you'll save money on your utility bills. Some customers have saved over 40% on their monthly heating and cooling bills.
What about winter heat loss?
Do you remember that Radiant Barrier is only 3% Emissive? That it only gives off 3% of heat, because the rest is being reflected? Here's a secret about aluminum: it's always 3% emissive, even if nothing is being reflected on the other side.
This means that in the winter, if you have Radiant Barrier on your attic floor, any heat that leaves your house is "caught" by Radiant Barrier.
Anything else?
Regular reflective insulation is a vapor barrier, Radiant Barrier isn't. This is important because you don't want to trap moisture in your attic. Radiant Barrier insulation is also:
- Non-Toxic.
- Never affected by humidity or condensation.
- Class A/Class 1 fire rated (the best possible fire rating).
- Easy to install -- no protective garments are necessary.
- Virtually indestructible -- Radiant Barrier will not collapse, compress, or disintegrate over time.
- Birds, rodents, and insects don't eat it, or steal it for their nests.
- Reasonably priced.
- Less expensive to ship than regular insulation.
Who else uses Radiant Barrier?
Believe it or not, Radiant Barriers are used a lot more than most people realize. For example: