Architects and builders use special siting, design and materials to absorb and distribute the sun’s heat and take advantage of sunlight to brighten interior spaces. Passive solar also refers to positioning shading devices to protect buildings from excessive heat. Passive solar does not have mechanical or special equipment like active solar. Instead, design is adapted to the local climate.
There are several ways to use passive solar to achieve direct gain, indirect gain, and insolated gain. Elements used are: absorber material (dark tile); thermal mass that retains heat during the day, then releases is during cooler evening and nights (trombe wall); aperture (south-facing glazed windows); distribution (allows air flow); and control (overhanging roof or deciduous trees to protect from heavy sun in summer, allowing more light in winter when sun is lower and leaves have fallen).
Passive lighting is another important way to reduce the need for electricity and cut costs. North-facing clerestory windows or a sawtooth roof along with south-facing windows add natural light. Flexible light tubes or skylights allow one to brighten interior spaces with limited or no windows.
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