Materials with high thermal mass—which have the ability to absorb, store, and reradiate heat—work
well for passive cooling. During the day, thick walls of concrete, adobe, or brick act as a heat sink,
absorbing energy. At night when temperatures drop, the mass slowly releases the heat. For maximum
effect, thermal mass must be exposed to the living spaces. High-mass buildings have up to three
square feet of exposed mass for each square foot of floor area