Trombe wall
From Wikipedia, the free encyclopedia
A Trombe wall is a sunfacing wall developed by the French engineer Félix Trombe 1956 in FontRomeu
OdeilloVia, 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.
In the original design, very little of the received heat ends up in the interior and most is lost to the
environment at night, because resistance to heat flow between the collector surface and the interior is the
same in both directions.
Current basic design
Modern Trombe walls have vents added to the top and
bottom of the air gap between the glazing and the
thermal mass. Heated air flows via convection into the
building interior. The vents have oneway flaps which
prevent convection at night, thereby making heat flow
strongly directional. This kind of design is an isolated
passive thermal collector. By moving the heat away from
the collection surface, it greatly reduces thermal losses
at night and improves overall heat gain. Generally, the
vents to the interior are closed in summer months when
heat gain is not wanted.
Nighttime thermal losses through the thermal mass can
still be significant. The modern design can be still further
improved by insulating the thermal mass from the
collection surface. The insulation greatly reduces
nigh