Trombe wall

Invented by Edward Morse in 1881, then revived in the '60s by Felix Trombe, a Trombe wall is a passive heat storage, which uses the thermal inertia of the massive walls involved.

Generally positioned in the south walls, Trobe wall consists of a series of components, each designed to obtain the maximum solar gain. The wall is essentially constituted by a solid wall of brick, stone or concrete, which goes to make up the thermal mass of the heat accumulation. The wall surface is treated with lacquer the dark, so as to attract better solar radiation (approximately 95% if it is black).

In this wall is approached a double plate glass at a distance of about 5-10 cm, which has both at the top and at the bottom, the slots for ventilation.

It is thus to create a wall element that traps solar radiation for the greenhouse effect which is to generate in the part behind the glass itself, which is then transformed into heat, which goes to accumulate in part in the wall itself, in part air interspace.

The openings so positioned, on a system of convective motions, allow a circular air passage: that warm, tends to rise and to enter the interspace in the indoor environment; this simultaneously pushes the cold air at the bottom, so that it can be sucked from the holes placed in the bottom.

Depending on the season, these holes are opened or closed, so as to facilitate the heating and cooling of the interior of the building.

In hot climates it is good also combine the use of adequate shielding, since the only solar radiation is able to significantly raise the temperature of the air in the cavity between glass and wall.

Excellent example of passive solar heating, the walls of Trumpets then function as solar collectors, which exploit the sun to heat the air present in the empty spaces, which act as cavity, mass between the inner wall and glass.

It's a versatile system, which must be suitably designed calibrating the thickness of the wall of accumulation, in new buildings, and the glass, if for renovation projects, for the purposes to obtain optimal efficiency.

Its ease of implementation and its involvement in the bioclimatic architecture, however, did not favor its spread in the past, partly because of the high cost of construction and partly because of the difficult to maintain, especially for large windows.

www.ispra.enea.it

arch. Valentina Caiazzo