Radiative heat excanges of people in complex geometry buildings: an experimentally based algorithm for computing angle factors

Abstract

Thermal comfort of people working or living in confined spaces depends, to a large extent, on the radiative thermal exchanges. These contributions are expressed, among other things, as a function of the mean radiant temperature that, in the general cases where there is a presence of high intensity sources, must be expressed as a function of the angle factors between subjects and the surrounding surfaces of enclosures. Angle factors, in turn, depend on the projected area factors. Despite this evidence, at the present there is a lack in the availability of simple and reliable methods capable of computing angle factors of people in assigned postures with respect to complex geometry buildings. In this work, a new algorithm is proposed for the computation of the angle factors of people within rooms characterised by complex shapes. The algorithm is based on the results obtained by means of an experimental photographic apparatus which allows measurements of projected area factors of seated or standing people in such complex confined environments. Finally, the algorithm for computing angle factors in complex geometric situations is applied to a dome building. The effectiveness of the algorithm in computing the local thermal conditions in the building is also shown.