Trombe Walls

Trombe walls are a form of solar heating which uses the natural buoyancy of air to circulate heat. Sunlight is absorbed by a dark external material. The heat from the solar radiation is stored in the large thermal mass of the wall for long periods before being transmitted to room when it is required. A trombe wall can take several hours to heat up and also several hours to discharge its heat so it can be used as a form of nighttime heating. During hours of daylight air circulates in the gap between the absorbing surface and a pane of glass which covers it. The air is circulated through openings at the top and bottom of the wall and is heated. The hot air rises and draws in more cool air to the bottom of the wall. Consequently, heat is transferred to the room.