Cooling Energy and Cost Savings with Daylighting

Fenestration performance in nonresidential buildings in hot climates is often a large cooling load liability. Proper fenestration design and the use of daylight-responsive dimming controls on electric lights can, in addition to drastically reducing lighting energy, lower cooling loads,speak electrical demand, operating costs, chiller sizes, and first costs. Using the building energy simulation programs DOE-2.1B and DOE-2.1C , we first discuss lighting energy savings from daylighting. The effects of fenestration parameters on cooling loads, total energy use, peak demand, chiller sizes, and initial and operating costs are also discussed. The impact of daylighting, as compared to electric lighting, on cooling requirements is discussed as a function of glazing characteristics, location, and shading systems.