Harper Construction Services

reflective barrier insulation
radiant barrier attic insulation
What is Radiant Barrier?

Radiant barriers are materials that are installed in homes to reduce summer heat gain and winter heat loss, and hence to reduce building heating and cooling energy usage. The benefit of attic radiant barriers is primarily in reducing air-conditioning cooling loads in warm or hot climates. Te radiant barrier that we use is a spray on application. It has highly reflective material, with different metals and aluminums in the coating.

How are radiant barriers installed in a residential attic?

Radiant barriers may be installed in attics in several configurations. The simplest is to spray the radiant barrier directly below the existing roof decking, below the surfaces of the attic truss chords or rafter framing.

How do radiant barriers work?

Radiant barriers work by reducing heat transfer by thermal radiation across the air space between the roof deck and the attic floor, where conventional insulation is usually placed.

A closely related material property is the "reflectivity" (also called the "reflectance"). This is a measure of how much radiant heat is reflected by a material. The reflectivity is also a number between 0 and 1 (sometimes, it is given as a percentage, and then it is between 0 and 100%). For a material that is opaque (that is, it does not allow radiation to pass directly through it), when the emissivity and reflectivity are added together, the sum is one (1). Hence, a material with a high reflectivity has a low emissivity, and vice versa. Radiant barrier materials must have high reflectivity (usually 0.9, or 90%, or more) and low emissivity (usually 0.1 or less), and must face an open air space to perform properly.

On a sunny summer day, solar energy is absorbed by the roof, heating the roof sheathing and causing the underside of the sheathing and the roof framing to radiate heat downward toward the attic floor. When a radiant barrier is placed on the attic floor, much of the heat radiated from the hot roof is reflected back toward the roof. This makes the top surface of the insulation cooler than it would have been without a radiant barrier and thus reduces the amount of heat that moves through the insulation into the rooms below the ceiling.

Radiant barriers can also reduce indoor heat losses through the ceiling in the winter. Radiant barriers reduce the amount of energy radiated from the top surface of the insulation, but can also reduce beneficial heat gains due to solar heating of the roof. The net benefits of radiant barriers for reducing winter heat losses are still being studied.

How does a radiant barrier differ from conventional attic insulation?

Radiant barriers perform a function that is similar to that of conventional insulation, in that they reduce the amount of heat that is transferred from the attic into the house. They differ in the way they reduce the heat flow. A radiant barrier reduces the amount of heat radiated across an air space that is adjacent to the radiant barrier. The primary function of conventional insulation is to trap still air within the insulation, and hence reduce heat transfer by air movement (convection). The insulation fibers or particles also partially block radiation heat transfer through the space occupied by the insulation.

Insulation is usually rated by R-value. Since the performance of radiant barriers depends on many variables, simple R-value ratings have not been developed for them. We have installed radiant barrier in 1,000's of homes around the Houston area.

Radiant barrier can reduce your energy costs and is by far the most cost effective home improvement you can do to save money every month on your heating and cooling costs. Call us today, we are the radiant barrier pro's!

Call us today for a free Radiant Barrier Estimate 281-905-2414

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Other areas we service are Houston - Greenway Plaza - Upper Kirby - Midtown Houston - Downtown Houston - River Oaks