What Is A Radiant Barrier?



The Science

radiant heat

A radiant barrier is a reflective insulation that can effectively block most of the heat entering or leaving your living space. Stopping radiant heat transfer is the surest means for reducing your heating and cooling needs. In summer, less radiant heat in your attic means that your air conditioning system will run more efficiently. In winter, when you want to keep the heat in, a radiant barrier can help your heating system run more efficiently by reflecting the heat inward.

Traditional insulating materials such as fiberglass, cellulose, and Styrofoam are able to absorb or slow down convective and conductive heat transfer. Radiant heat transfer is seldom discussed, but is a dominant form of heat transfer which traditional insulation does not block. The chart below explains the differences between these 3 types of heat transfer.

In your home, radiant heat is generated from charged particles converted into electromagnetic radiation. Radiant heat sources include sunlight streaming in a south or west facing window, a fireplace, or a radiator linked to a central boiler. It moves through the air without actually heating the air. The objects that are in the path of the charged particles, however, absorb the energy and heat up, radiating heat to other objects (like people) in the room. Everything in proximity to that space feels warmer.

Hot and Cold Facts

solar snap radiant heat

Radiant barriers are usually installed in the attics of homes. In warmer climates, radiant barriers are usually found under the roof rafters, reflecting back the heat generated when the sun meets the roof. Since the amount of heat meeting your home’s insulation has been largely blocked, the heat of the attic’s air temperature is greatly reduced. Anyone who has been in an attic on a hot, sunny day can appreciate this. Radiant barriers, then, protect ductwork and any items stored in an attic.

In cooler climates, radiant barriers work to prevent heat from the lower levels of the home from escaping. It is important to have a tight air seal in the attic at all times but, in combination with a radiant barrier, homeowners are going to significantly save on heating bills.

Benefits of Adding a Radiant Barrier

Adding a radiant barrier to work along with your current insulation can have great benefits. These include:

  • Blocks up to 97% of radiant heat in the attic, saving up to 35% of home energy costs from the attic space’s impact on the energy use
  • Reduces work load and extends life of HVAC system
  • Lowers humidity in air conditioned areas
  • Increases comfort in both air conditioned and non-conditioned areas
  • Will increase comfort during colder seasons
  • Reclaims potential storage space, protecting items from excessive heat

What To Look For:

Radiant barriers come in rolls of thin, highly reflective material, usually over 90% aluminum. The reflectivity of a radiant barrier should be as close to 100% as possible, and the emittance level should be close to 1-3 %. This means that less thermal radiation is emitted, and the heat from the roof will be reflected back. Look for a barrier with a denser, heavier weight and tensile strength – preferably one that has a woven fiber to prevent ripping and tearing upon installation. It will also discourage rodents from nesting, because they can’t use it for nesting materials.

There are so many benefits to installing a high quality radiant barrier in your home that many communities actually require it. In moderate zones it won’t have the money saving capabilities of colder and hotter climates, but a radiant barrier is a good investment wherever you make your home.

Radiant barriers have been tested by:

Oak Ridge National Laboratory                                                                          

Florida Solar Energy Center http://www.fsec.ucf.edu/en/publications/html/fsec-en-15/

U.S. Department of Energy http://sigmalabs.squarespace.com/storage/reference/DOE%20Radiant%20Barrier%20Study%202012.pdf

The Evolution of Radiant Barriers

Radiant Heat Barriers are nothing new, they have been used since the 1920’s in commercial and residential buildings.

How it all began: Patent on Reflective Surfaces as Building Insulation

In 1925, two German businessmen, Schmidt and Dyckerhoff, filed for patents on reflective surfaces for use as building insulation. Aluminum was no longer classified as a precious metal, so it became a commercially viable option. This became the launching pad for radiant barrier and reflective insulation around the world, and within the next 15 years, millions of square feet of radiant barrier were installed in the United States alone.

                                                                            infra insulation display 1953

                                                                            infra insulation display 1953

Radiant Barrier Commercially Produced

In 1945, Alexander Schwartz, president of INFRA Insulation, Inc. commercially produced a radiant barrier reflective insulation product designed to keep summer heat out and winter heat in a home or building. INFRA Insulation, Inc. quickly became the largest producer of reflective foil insulation.

In the 1950’s, INFRA Insulation was introduced to the consumer market as an accordion-fold style product and was advertised as easily installed by anyone who could use a staple gun. Newspaper and magazine advertisements even depicted women installing the radiant barrier in their own homes.

NASA Uses Radiant Barrier

In 1955, Clark E. Beck engineered the technology at NASA’s request at the Wright-Patterson Air Force Base. NASA was trying to find a way to protect astronauts during space walks from extreme temperature shifts. If they attempted to use conventional insulation, they would have to have a seven-foot thick protective layer on the space suit.

The radiant barrier created was able to reflect 95% of the sun’s radiant heat while also reflecting the astronaut’s body heat back at them to keep them warm. Reflective insulation was then used in spacecrafts, equipment, and astronaut’s suits to protect them from thermal radiation and retain heat from the fluctuating  extreme temperatures of outer space. Radiant barriers are still used in most spacecraft today.

Obstacles In Consumer Market

In the following years, several companies began to market their own reflective foil insulation for consumer homes and businesses. They were met with opposition from large corporations that produced traditional insulation (fiberglass and cellulose). They recognized that radiant barriers were more affordable, lightweight, and effective, therefore, a huge threat to their product.

The traditional insulation industry spent millions of dollars in marketing and educating consumers on the need for an R-value rated insulation product. Since radiant barriers do not have R-values (because they work entirely different than traditional insulation), consumers were swayed from purchasing and using reflective radiant barrier insulation.  Architects and engineers, however, continued to learn more about its advantages and incorporate it into their plans.

the evolution of radiant barriers

Radiant Barrier Today

Today, radiant barrier technology has been spun-off into products as diverse as energy-conserving building insulation, agricultural insulation, automobile insulation, protective clothing (like used by firemen), and many other products.

Radiant barrier insulation is commonly used in homes, businesses, and government buildings. Radiant barriers are recognized by The U.S. Department of Energy as an effective, cost-cutting solution, especially in hot climates.

rhino hide radiant heat barrier

The most common radiant barrier installed in existing homes is a reflective foil insulation that comes on a roll. These radiant barriers are usually stapled to the underside of the rafters. This is a very time consuming process and in many homes, there are hard (or impossible) to reach places making it difficult to complete installation correctly.

The newest innovation is Rhino Hide’s Solar- SNAP Radiant Heat Barrier, which contains steel spring battens every 2 feet. This allows the product to be rolled between trusses and conventional framing. Not only can you easily reach tight and high spaces, it reduces the installation time by as much as 75%. It is also easily removed and replaced for inspection and repairs.

To learn more about the benefits of Solar-SNAP Radiant Heat barrier or to become a certified installer Contact Us Today.