High Quality Content by WIKIPEDIA articles! A Trombe wall is a sun-facing wall developed by the French engineer Félix Trombe 1956 in Font-Romeu-Odeillo-Via, and is built from material that can act as a thermal mass (such as stone, metal, concrete, adobe or water tanks), combined with an air space, insulated glazing and vents to form a large solar thermal collector. This idea was popularized as a glazed, heavy wall. During the day, sunlight would shine through the insulated glazing and warm the surface of the thermal mass. At night, heat would escape from the thermal mass, primarily to the outside. Because of the insulating glazing, the average temperature of the thermal mass can be significantly above the average outdoor temperature. If the glazing insulates well enough, and outdoor temperatures are not too low, the average temperature of the thermal mass will be significantly higher than room temperature, and heat will flow into the house interior.