Passive options for thermal comfort in building envelopes—An assessment

Abstract

Building envelopes that have been developed so far often require mechanical systems involving expensive equipment utilising fuel and electrical energy for thermal comfort. These sophisticated systems (active systems) cannot be adopted by an average person in developing countries because it is difficult to afford and to maintain them. A study conducted by the author in a Ph.D. programme at the Bartlett School of Architecture and Planning, University of London, U.K., examines the building envelope of houses common in the Delhi region of India. The thermal environment in a traditional building envelope is determined, an index quantifying discomfort is established, and the degree of discomfort calculated. A vailable passive options for modifying the internal climate of building envelopes are considered one by one and an attempt is made to examine how far the thermal discomfort can be controlled with each of these options. The extent of the integrated effect of passive options is also established. The methodology of computer simulation is used to determine the thermal performance of different alternatives. It is concluded that two-thirds of the discomfort can be eliminated by the judicious use of simple passive options based on thermophysical properties and configuration of building envelopes.