Daylighting aspects of the DOE passive commercial buildings program

DOE has conducted a program to assess passive solar heating in non-residential buildings. Data regarding the daylighting aspects of ten projects is presented in this paper. All ten buildings use daylighting--by various strategies such as lightshelves, clerestory, roof monitor, or skylight--as a primary element in their design. A ''percent aperture'', the ratio of the glazed solar aperture area to the building floor area, is arrived at, to allow for comparison of projects. It is found that a decrease in the amount of auxiliary lighting requirements occurs with an increase in percent aperture. Also, the amount of total auxiliary energy decreases with increase in percent aperture. After one year performance evaluation the projects are expected to utilize approximately 50% less energy than conventional designs.