Measurements of solar radiation and illuminance on vertical surfaces and daylighting implications

There is a growing concern about the rapid development of infrastructure an d building projects and their likely impacts on the environment. Particular concerns have been raised about office building developments and energy co nsumption issues. In recent years, there has been increasing interest in us ing daylight to save energy in buildings. Lighting control integrated with daylighting is recognised as an important and useful strategy in terms of e nergy-efficient building design. It is believed that proper daylighting sch emes can help reduce the electrical demand and contribute to achieving envi ronmentally sustainable building developments. This paper presents a simple method for estimating the likely energy savings in electric lighting due t o daylighting and the possible cooling penalty. Vertical solar radiation an d illuminance data measurements are described. Cumulative frequency distrib utions of daylight availability are reported. The likely energy savings in office buildings are determined based on on-off and top-up controls, and th e energy and environmental implications are discussed. (C) 2000 Elsevier Sc ience Ltd. All rights reserved.