Daylighting through light pipes in the tropics

Daylighting possesses good potential for application in the tropics, where the sky is luminous. But the depth of penetration of skylight through side windows is limited and can be complemented by sunlighting for illumination of the deeper interior space of a building through light pipes in the ceiling plenum. Modeling of the mechanisms of light delivery and heat transfer will enable trading off between light gain, increased air-conditioning load, and overall system performance and cost. This paper reports the development of such a model based on a general configuration of a plenum in a test room and a comparison of the calculation results with results from physical measurements. (C) 2000 Elsevier Science Ltd. All rights reserved.