Optimum distribution of insulation inside and outside the roof

Abstract The accurate prediction of the rate of heat flow through walls and roofs made of several layers of different materials is a problem of practical importance in the design of buildings and their associated air conditioning systems. In this paper we have investigated the optimum distribution of a given total thickness of insulation inside and outside the roof for achieving the maximum levelling in the heat flux entering through the roof. It is seen that this is achieved when the thicknesses of insulation inside and outside the roof are equal. The implications of this result in reducing the required capacity of air-conditioning plants have also been briefly discussed.