Definition of a Radiant Barrier

The Reflective Insulation Manufacturers Association International (RIMA-I) recognizes and supports the ASTM standards for radiant barriers specifically ASTM C1313, ASTM C1158, and ASTM C168. Radiant barriers function by reducing heat transfer by radiation. The thermal performance or the reduction of radiant heat transfer is directly proportional to the surface emittance of the radiant barrier material. Emittance measurements of all materials range between zero (0), no radiant heat transfer, and one (1) that of a black surface or complete radiant heat transfer. Common building materials, such as wood, masonry, and fiberglass insulation have surface emittances of approximately 0.85 and therefore have high radiant heat transfer rates. Products defined as radiant barriers have surface emittances less than or equal to 0.1 or low radiant heat transfer rates. For more information please contact us or call 1-800-279-4123