Analysis of passive heating concepts

Abstract Based on Fourier series solution of the heat conduction equation, a mathematical model has been developed to analyse the thermal performance of some typical passive heating concepts, namely the Trombe wall, Water wall and Solarium in two cases, (i) when the glazing is left uncovered thoughout and (ii) when the glazing is covered with an insulation during off sunshine hours. The model yields analytical expressions for the time dependent heat flux entering into the living space, which is assumed to be at a constant temperature corresponding to an air conditioned room. Numerical calculations corresponding to the meteorological data of a typical cold winter day in North America (Boulder, 13 January) show that from the point of view of thermal load levelling and average heat flux into the room, the solarium is best when the south glazing is not covered with a night insulation. In the case when night insulation is used a water wall is, however, found to be the best; a 0.10 m wide water wall followed by a 0.22 m thick concrete wall gives almost a constant heat flux into the living space.