Attic Radiant Barriers

It has been a really hot summer here in Houston. So, we've been thinking a lot about ways to reduce energy bills during these steamy months. One way to reduce cooling costs by upwards of 10% is to install a radiant barrier in your new or existing home.

A radiant barrier is a highly reflective, low-emitting material that intercepts the flow of radiant energy to and from building components. They come in a variety of forms including reflective foils and reflective laminated roof sheathing.

The way radiant barriers work:

Radiant energy from the sun heats up our roofs. It doesn't take long before the absorbed heat travels by conduction through the roofing materials to the attic side of the roof. The hot roof material then radiates its gained heat energy onto the cooler attic surfaces, including the air ducts and the attic floor. A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic by reflecting the radiant heat rather than absorbing it.

Installation Options:

Radiant barriers are most effective in hot climates, reducing heat costs and possibly even allowing for a smaller cooling system.  Be sure to intall the barrier with the most shiny, reflective surface facing the attic space. There are 3 typical installation locations: 

1: On the underside of the roof sheathing. This can done with foil-faced osb sheathing or with rolled foil that drapes between the rafters.

2: Applied to the underside of the roof rafters. This is very effective method because it leaves an air gap for ventillation between the attic space and the hot roof.

3. On the attic floor. This is the least effective method if you have attic HVAC equipment. It also leaves the reflective surface susceptible to dust.

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Stay cool, Houston!

For more information on radiant barriers Visit the Department of Energy's website. And, for more ways to cool your roof, check out USGBC's green home guide.