INVESTIGATIONS ON SOLAR RADIATION AND ILLUMINATION FOR CLEAR ATMOSPHERIC CONDITIONS AND THEIR APPLICATION TO BUILDINGS IN INDIA

Abstract

Of all the elements that together make up the physical environment of buildings, thermal and visual components are of relatively greater significance. The electromagnetic radiation from the sun(direct) and the sky(diffuse), is one of the major factors that influences these thermal and visual components to a great extent. Therefore, in solving the problems of building environment, a precise quantitative knowledge of these thermal and visual components of both direct and diffuse solar radiation, is a necessary pre.. requisite. Besides this, a kriowledge of diurnal and annual variation in solar positions with respect to building facades is needed to estimate the radiation that is incident on a given surface of a building at a particular time or over a period of time. In present day buildings cooling load of building is greatly influenced by solar radiation due to excessive use of glazed areas and, therefore, the solar radiatioh data should be precisely detr:rmined. This sort of information is equally important in utilization of the radiant energy Of the sun for heating and cooling with a view to improve the functional efficiency of building enclosures. Although the problems of solar effects on buildings had been realized by ancient thinkers in Greece, Egypt and India, the nature of present day problems are much more wider, irm•■••••••••••■•..... complex and multifaceted involving influence of solar 3.11 radiation on heat transfer through glass and other building fabrics. Similarly, for proper design of building fenestra-tions for providing adequate daylight indoors for various tasks, accurate quantitative assessment of solar illumination, i.e., solar radiation in the visible region of the spectrum evaluated in terms of response of human eye, is equally important.