Summer heat gain, the process whereby exterior heat migrates into attics and loft voids, can be costly. It increases the work your air conditioning system must do to keep the building cool, which translates directly into increased energy costs.
Radiant barriers are a simple solution to heat gain in the attic. The sun’s heat is a form of radiant energy, which is absorbed by the object it falls on – in this case, your roof. The barrier works by reflecting the radiant heat back outside, rather than letting it penetrate from the underside of the roof into the attic.
If you have ductwork in your attic, it’s vulnerable to heat gain that’s conducted through the roof. Cool air traveling through attic ducts can get warmed, forcing your cooling equipment to work all the harder to satisfy the set temperature on the thermostat. In addition, heat gain in the attic can warm the attic floor and infiltrate your living spaces below. Radiant barriers “bounce” the sun’s radiant heat away from the attic.
The performance of a radiant barrier can be affected by three factors:
- The angle at which the sun’s radiant energy is striking the outside of the roof (rays at right angles to the roof are most powerful)
- The reflectivity of the radiant barrier itself
- The amount of radiant energy leaving the underside of the barrier and continuing inward, called emissivity
Reflectivity is sometimes expressed as a percentage. The higher the number, the better the barrier will perform and the greater savings you are likely to notice.
Most radiant barriers have a reflectivity of between 95 and 97 percent, which the U.S. Department of Energy says will reduce cooling costs 5 to 10 percent in a warm, sunny climate.
Several types of radiant barriers are available, including foil, roof sheathing, reflective roof shingles, and even reflective chips scattered over loose-fill insulation. The trained and certified technicians at Ernst Heating & Cooling guarantee proper installation. Contact us to arrange an on-site consultation to learn more about how a radiant barrier can be a simple way to counter heat gain in your attic.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about radiant barriers and other HVAC topics, download our free Home Comfort Resource guide.