Abstract: | The ability of an external opaque wall of a room to perform two functions, i.e. to store the thermal energy when it reaches thermal equilibrium under solar radiation, and to exploit the stored thermal energy during the transient phenomenon of the wall thermal restoration after the interruption of solar radiation flux, was analysed. Analytical expressions have been obtained for the ability of the wall to store and exploit solar radiation, and for the resulting thermal gain of the room during the transient state of its thermal restoration. |