How Does a Radiant Barrier Work?

Posted by Ecofoil on

Photo of Austin Austin Dopp EcoFoil BUF™

It is safe to say that radiant barriers may be one of the most misconstrued energy-saving products in the marketplace today. A radiant barrier is a layer of metallic foil that blocks radiated heat, assisting in the energy performance of a building. In short, do these products save energy? Yes, but it is very important to understand certain things about radiant barriers. First, since Ecofoil Radiant Barrier reflects 96% of radiant heat does not mean it will reduce your bills by 96% each month. The other thing of importance is to understand how radiant barriers work.

Heat Transfer

Explaining how radiant barriers work is somewhat of a 3-part process. There are three different types of heat transfer: Conduction, Convection, and Radiation. As you know, heat travels from warmer air to colder air. When you touch something warm, that form of heat transfer is known as conduction. Essentially, heat is conducting from one molecule to the other. Insulation reduces this effect because it traps air, in turn, slowing down the flow of heat.

Heat energy which is transferred between a surface and a moving fluid at different temperatures is known as convection. Insulation reduces this effect because it traps air, in turn, slowing down the flow of heat.

The third and final method of heat transfer is transfer by radiation. For many people, it is a bit more difficult to understand radiant heat flow. Radiation is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles transmitted as heat, light and electricity. The best example of radiation that comes to mind is the sun. Between the sun and the earth’s atmosphere there is no air to conduct or convect energy. Energy from the sun radiates through space and is not converted to heat until it hits matter like air in our atmosphere, your car seats, or a home’s roof.

Three types of heat transfer.

Some Examples of Radiant Barrier Around You

There are several examples of radiant barrier materials being used daily that many people don’t even realize. For example, sunshades in vehicles which help keep the interior of the vehicle cooler than normal on a hot day. Pizza delivery bags which help keep deliverable pizza hot and fresh until the moment it arrives at your door. The inside lining of winter/skiing jackets which help keep you warm and dry while you are on the slopes. Last, but not least is the insulated drinking cup, which works so well at keeping your drink hot or cold. Now, you may be asking yourself, what do these products have to do with EcoFoil Radiant Barrier?

The answer to this question is quite simple. Much in the same way that the insulated cup works to keep radiant heat from penetrating through it, keeping your drink hot or cold, radiant barrier will do the exact same thing with a dead air space on one side of it. In our homes a dead air space is required on one side of the radiant barrier. This allows the radiant barrier to reflect 96% of the radiant heat away from it and only allow 4% through it, making the product a no brainer to use in many applications. Much like our Perforated Radiant Barrier which we use in an attic space to keep warm summer heat from penetrating through the roof.

Testimonial from Beverly H.

If you would like any other information on EcoFoil Radiant Barriers, please give us a call at 888-349-3645 or send us an email at We look forward to hearing from you soon!