Reflective technology that is used to reduce energy use in buildings is represented by three commercially available product types. In all three cases the performance of the reflective product depends on reduction in radiative transport across air spaces due to low thermal emittance surfaces.
Products identified in North America as 'radiant barriers' typically have a low-emittance surface adjacent to a relatively large air space that may be ventilated or unventilated. The performance of radiant barriers is related to reduction in thermal radiation from the low-emittance surface, which is directly proportional to the emittance at a specified surface temperature.
Surfaces with low-emittance coatings perform much like radiant barriers. The coating for the surface, known as interior radiation control coating (IRCC), reduces radiative transport in the same manner as radiant barriers. Radiant barriers and IRCCs are not typically assigned thermal resistance values (R-values).