This folding screen is an object that becomes slightly warm thanks to a layer of Phase Change Material included in its structure that works as energy storage.
It is intended to give a sensation of comfort to people who stand next to it, they reduce radiation loss to the cold surfaces of the room (for instance cold walls and windows). It should be useful for instance in large spaces, such as offices, or to avoid a sensation of cold due to the presence of a window, especially in the evening, when the dark sky causes big losses of energy by irradiation.

Phase Change Material included in this object are Glaubert salts. Once decided the temperature that we want to be reached by the panel, the kind of salt to be used will be determined, in order to assure that temperature. The amount of it can be calculated in relation to the performance endurance.
At first salts will be melted by heat; the latent heat that they accumulate during the change of phase from solid to liquid will be given back later when they become solid again. During the change of phase salts keep constant their temperature so all the process is isothermal and this happens at a designed temperature, as ice that melts into water at a constant temperature of 0° C. The difference and crucial point consists in the phase change temperature. A salt that solidifies at 32° C theoretically keeps its temperature at 32° C for hours, up to the complete transformation, maintaining the folding screen warm.

This folding screen with salts that melt thanks to solar irradiation. It should be put very close to a window oriented to south in order to profit of irradiation.