Using high light reflectance acoustical ceilings to increase the energy efficiency of buildings

Abstract

Acoustical ceilings with white, highly light‐reflecting surfaces can be used as an effective, passive means to significantly improve the energy efficiency of a space. When a ceiling with high light reflectance is coupled with an indirect lighting system, illumination can be increased by 20%, or the energy directly associated with lighting can be reduced by 20%. In addition, lower lighting loads can reduce cooling costs by 7%. A highly light reflective ceiling can also be used to reflect daylight into a space, increasing the amount of light in interior areas away from the windows by as much as 20%; alternatively, the surface area of windows may be reduced by 14% while maintaining the same illumination levels. In all cases, the increased reflectance of light allows the number of fixtures to be decreased, further increasing the savings related to both energy and maintenance. The percentage of energy savings associated with lighting is proportional to the percentage increase in the light reflectance value; therefore, even small increases in light reflectance provide increases in energy efficiency. When the acoustical performance of two products is comparable, light reflectance could be a critical differentiator in determining total building performance and occupant comfort.