Radiant Barriers Go Beyond Insulation For Heat Efficiency

Heating air is expensive! Cooling air is also expensive -- so it makes sense that if you don't have to condition air as much, you'll save on your utility bills.

Insulation and radiant barriers are used in buildings to keep heat in during the winter...and keep heat out during hot periods and seasons. But most buildings weren't optimized for energy efficiency in both hot and cold temperatures.

"There's no such thing as heat and cold," my husband told me, "only heat and less heat." Practically speaking. Of course, absolute zero is pretty cold, but in the everyday world of conditioning the air of our homes and workplaces, heat and less heat is a good way of thinking about temperature flow, changes and controls.

That's where radiant barriers and insulation come into a tug of war.

Radiation, Convection and Conduction - 3 Types of Energy

The summer sun produces a lot of radiation.

Winter heating inside the home produces mostly convection and radiation.

In essence, the heat flows inside out in the cold winter -- and outside in in the hot summer. Insulation slows the heat movement down, but doesn't stop it's movement.

Foil covered barriers reflect the heat and in essence, stops it from entering the other side of the barrier.

Radiant Barriers Research

Tests by the Oak Ridge Laboratories in Tennessee, and the University of Mississippi support those findings.

Using infra-red thermography, heat transfer has been tested for resistance differences between radiant barriers and insulation. These photos show significant resistance to heat transfer over regular insulation.

Radiant Barriers for Buildings

• The reflective surface reflects long wave radiant heat that strikes it -- up to 97% of all radiant heat.
• Close contact, but non-touching, allows reradiation to happen, and when you reduce the amount of heat that "gets through" the radiant barrier, you will have less convection taking place.

Applications for Foil Radiant Barriers and Insulation

Radiant Barriers

• Attics that need additional insulation
• Under roof decking
• House wrap
• Metal buildings
• Fire walls
• Vapor radon barriers

Reflective Insulation

Common applications of reflective insulation include:

• Building walls
• Pre-engineered metal buildings
• Agricultural buildings
• Vapor/radon barriers
• Duct or pipe wrap
• Crawl spaces
• Basement walls
• Water heater wrap
• Post and beam construction
• Under concrete radiant heat floors
• Thermal packaging
• Automotive

Energy Star Benefits

By combining Energy Star best practices for insulating your building, such as weatherizing the cracks and crannies, and insulating exposed surfaces properly, Energy Star research can help you develop a plan to keep your heat where you want it -- and lower your utility bills!

ENERGY STAR considers insulation to be products or materials that meet the FTC's definition of "home insulation" ("any material mainly used to slow down heat flow") and are used to insulate a whole wall, ceiling, or floor. These products include, but are not limited to: fiberglass, cellulose, mineral wool, whole-wall spray foam, rigid foam board, cotton fiber batts, and foil radiant barrier products.

Tax incentives and utility company rebate programs often include insulation in programs that offset some of the initial costs of installing energy-saving insulation. And by reducing your energy use, you not only save on your monthly utility bill, but reduce the need to generate that energy, which reduces greenhouse gas and heat that impacts our environmental systems and weather patterns. And that saves lives and money in the long term, as well.