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Index

Products, Technology, Programs, and Key Announcements

• How Does a Radiant Barrier Work?
• Natural Linoleum Flooring

How Does a Radiant Barrier Work?
As the summer months approach, so goes the comfortable home from mild to hot. A large portion of the heat load on the house comes through the ceiling area, a mirror of the floor space. It is very important to have adequate insulation between the living space and the attic space, but little attention is paid to the space between the roof and the elements.

One solution is to have a light colored roof to reflect the incident solar heat energy, which works to a certain extent, but what if you could place mirrors over your entire roof to transfer the rays from the sun away from the attic space, cooling equipment, and ducting stored in the attic? This is the idea behind radiant barriers. A radiant barrier usually is sheet of reflective material that is placed under the roof deck to transmit the heat gain from your roof back out to the environment. Usually the sheet is made of aluminum on a kraft paper backing or sometimes foam insulation. Many factors effect the efficacy of the radiant barrier including the cleanliness of the mirrored surface, placement of the barrier, and surface area covered.

As a brief primer to heat transfer, heat can move through three independent means or modes. First is through conduction, or how an oven bakes cookies, which in a home batt insulation tries to remedy. Next is convection, or blowing across a cup of tea, which in a home fans or blowers enable. Finally there is radiative heat transfer, or how a vacuum container (Thermos) keeps things hot and cold. The radiant barrier primarily attacks infiltration of thermal radiation by reflecting the heat away from the cooler attic space. For the barrier to be effective there must be an air gap of a least 5 cm (2 inches) between the material and the roof line.

Several ways exist to attach the radiant barrier to the roof rafters including stapling the barrier to the underside of the rafters themselves, leaving a gap of the thickness of the rafters to act as the air gap. In new or replacement construction, the barrier is draped over the underside of the roof deck leaving a air gap like waves. For more information of the effectiveness of radiant barriers and to see if its use may apply to your climate look at:

• Florida Solar Energy Center
• Energy Efficiency and Renewable Energy Clearinghouse

Natural Linoleum Flooring
People are looking for ways to reintroduce natural materials into the home. A simple and beautiful ways is use natural linoleum flooring. It is easy to confuse natural linoleum flooring for vinyl flooring since the names are at times considered interchangeable, but if you specify natural linoleum, it is harder to get another product. The traditional characteristics of this floor is the swirl pattern of the wood flour, rosin, linseed oil, and cork on a jute backing making a pattern that goes through the floor, unlike printed or wear layer style vinyl flooring. You can also find natural linoleum in solid colors and other striking patterns.

Three major players exist in the manufacture and distribution of natural linoleum flooring:

• Forbo Industries
• DLW/Armstrong
• Domco