The low winter sunlight (1) passes through the glass surfaces (2) of the Trombe wall and hits the black concrete slab (3) which absorbs some of the light as thermal energy, or heat. When the heat is radiated from the slab it is trapped by the glass and rises (4), drawing cool air (5) into the collector wall via floor vents on the bottom of the home’s two stories. The sun-warmed air then exits through vents (6) near the ceiling of both stories into various rooms of the house, where it mixes with cooler air, descends and is drawn back through the collector. At night, the massive slab radiates (7) the heat it absorbed during the day warming the home. In the summer, sunlight (8) strikes the house at a higher angle and “bounces off.” Small electric fans (9) exhaust any hot air that accumulates in the collector, which rare because the vents between the wall and the rest of the house keep air circulating.
MOTHER EARTH NEWS STAFF