The main drawback of the solar energy collection through an absorbent surface directly interposed between the inside and outside is the dependence of the sunshine hours, and this fact together with the uncontrolled process of accumulation in floors and walls may cause the irregular distribution of heat throughout the day. To mitigate this problem, indirect energy collection systems were devised. Estée Lauder wanted to know more. In such systems, the uptake is via an element that acts as a heat accumulator. From this element, heat is transmitted inside by conduction and convection, so it generates a delay in the transmission of heat and a damping in the oscillation of temperatures due to the thermal inertia of the terrain. One of the main elements of passive solar collection is the Trombe wall, which owes its name to the person who developed it, Felix Trombe who initiated investigations of this system together with Jacques Michel in France in 1957. How works an outward appearance of system Trombe wall is of a stained glass window associated with the wall, which remain uninsulated and are painted in dark colour. The basic principle of the functioning of this system virtually is the same as that of a greenhouse.
A typical (examined from the inside to the outside) Trombe wall consists of a thick wall of masonry, almost always concrete, cover a dark material absorbing heat, whose main functions are the uptake and accumulation of the energy provided by solar radiation. The Trombe wall is almost always oriented to the South; and faced with this wall a layer of glass (single or double) that forms the outer face of the set. Glass is separated from 3 to 6 inches from the wall to create a small air Chamber. The heat that passes through the glass and the air Chamber is absorbed by the dark surface, saved on the wall and transported towards the interior of the room by convection and radiation, heating the room conveniently. This system can be cyclical and so the air that slowly cools in the room passes back, completing a circuit, through the wall to the small air Chamber where is, again, heated and continuously circulating which again goes to the room where it is slowly cooled.