BUILDING ENERGY EFFICIENCY AND FIRE SAFETY ASPECTS OF REFLECTIVE COATINGS

Radiant energy exchange between the exterior surfaces of buildings and the environment has a significant impact on both the energy requireme nts for cooling and heating, and on fire safety. These issues of energ y efficiency and fire safety are usually examined separately, but in t his paper the interaction between these issues is discussed, with emph asis on reflective coatings. The important spectral ranges for radiant control are, in micrometers (mu m), 0.3-2.5 (sunlight), 4-40 (300 K e nvironmental thermal radiation) and 1-10 (fire). Benefits can be obtai ned from the development of improved coatings which reflect adverse en ergy flows and absorb (and emit) favorable energy flows. As a specific important example, white coatings with high solar reflectivity and hi gh IR emissivity can significantly reduce energy use for cooling. Anot her benefit of high IR reflectivity in the 1-10 mu m wavelength range is enhanced fire safety due to the reflection of IR radiation emitted by fire. Due to overlap of the fire spectrum with both the solar and 3 00 K thermal spectra, fire retardant coatings can either enhance or im pair energy performance. From a research and development point of view there is considerable synergism between coatings for improved energy efficiency and fire safety. Technology developed for improved energy e fficiency can be adapted (transferred) to coatings for reflecting fire radiation, and vice versa.