Thermal Behaviour of Composite Walls Under Solar Irradiation and Internal Intermittent Heating

The problem of the room temperature oscillation under intermittent heating and solar irradiation is analyzed for two types of walls which have the same thermal conductance and different heat capacities. The yearly time- dependence of the sol-air external temperature is simulated by means of a Fourier's expansion, the coefficients of which are linear functions of time. In this way the analysis deals with the yearly transient state. The calculations show that the amplitude of the room temperature oscillations is markedly smaller, and nearly independent of the beginning instant of heating, in the case of walls having larger heat capacities. The effects of lack of solar irradiation or intermittent heating are also studied.