Sourcebook Passive Solar Design Sustainable Sources 1994-2000. Sustainable Sources 1994-2001. In this approach, the building itself or some element of it takes advantage of natural energy characteristics in materials and air created by exposure to the sun. Passive systems are simple, have few moving parts, and require minimal maintenance and require no mechanical systems. Operable windows, thermal mass, and thermal chimneys are common elements found in passive design.
Operable windows are simply windows that can be opened.
Thermal mass refers to materials such as masonry and water that can store heat energy for extended time. Thermal mass will prevent rapid temperature fluctuations. Thermal chimneys create or reinforce the effect hot air rising to induce air movement for cooling purposes. Wing walls are vertical exterior wall partitions placed perpendicular to adjoining windows to enhance ventilation through windows. Passive design is practiced throughout the world and has been shown to produce buildings with low energy costs, reduced maintenance, and superior comfort.