A university study of Centex Corp.'s (NYSE:CTX) Energy Advantage homes released Wednesday determined that radiant barrier insulation installed on roof systems reduces heat build up and signficantly improves the efficiency of HVAC systems.

The study, performed last summer by the Energy Center of Appalachian State University, compared a pair of adjacent four-bedroom Centex model homes in Charlotte using a total of 61 senors installed in and outside of the houses. It found:

* A 23-degree drop in the peak attic temperature in the home outfitted with radiant heat barrier versus the similar home without the barrier;

* A 20% reduction in the run-time of the air conditioning unit during the seven hours of peak attic temperatures;

* A 57% improvement in the efficiency of cooled air delivered through the air ducts during the same period.

"This particular study showed the installation of a radiant barrier in an attic can make it easier for your air conditioner to do its job in the summer heat," said Jeff Tiller, P.E., chair of the ASU Technology department. "That translates to lower electricity usage, which also impacts the carbon footprint of homes."

"Radiant barriers are a key feature of our Centex Energy Advantage suite of energy efficiency features," said Clayton Traylor who heads environmental affairs for Centex. "We're very pleased that this study validates the significant energy saving benefits our customers can expect from owning a Centex Energy Advantage home."

Centex began building its homes with radiant barrier roof decking in January of 2009 as part of its Centex Energy Advantage suite of energy-efficient features. According to the company, homes with Centex Energy Advantage features have been shown to have an overall energy efficiency gain of up to 22% over comparable homes built to the most widely used energy efficiency code, according to the NAHB Research Center.

The study was funded by a U.S. Department of Energy Building America grant provided through the North Carolina Energy Office.