May 20, 2006–June 24, 2007, National Building Museum, Washington, DC. The exhibition The Green House includes several interactive features – including its very own heliodon. Heliodons or "sun machines" are devices used to simulate the sun’s movement in relation to a structure. A heliodon can be configured to observe sunlight and shading patterns for clear sky conditions anywhere in the world. It does this by adjusting for season, time of day, and site location. Architects and builders study these patterns to orient a house in a way that optimizes natural heating and cooling.
www.nbm.org/Exhibits/greenHouse2/goGreen/goGreen.html