Multi-layered wall design to optimize building-plant interaction

In this paper the building envelope suitable for making easier the purpose of the air-conditioning plant to keep the indoor air temperature constant against impulsive external temperature excitation is investigated. For this aim two different criteria can be assumed: the peak power minimization or the average time length maximization of the air-conditioning plant working step. Among all possible multi-layered walls, the symmetrical three-layered one, with the high heat capacity layer between two equal layers made of insulating material, turns out to be an excellent compromise fully satisfying the first criterion and, with good approximation, the second too. All the other usual walls, in particular the homogeneous single-layered ones, as well as the two-layered ones with the insulating layer disposed on the wall outer or inner face, and the three-layered ones with the insulating layer disposed in the mid-plane of the wall, have turned out to be distinctly worse.