UNITS / TERMS:
The five elements of passive solar design include:
Aperture Collector: typically glass, the aperture collector is the area through which sunlight enters the home or building.
Absorber: the absorber is typically a hard, darkened surface on the storage element that sits in the path of sunlight and absorbs its heat.
Thermal Mass: the material(s) that retain the heat absorbed by the absorber. Thermal mass can be composed of water, concrete, stones, bricks, tile or other materials with high specific heat capacity.
Distribution: the means by which the solar heat is transferred from the storage material(s) to areas of the home or building.
Control: elements that control the under- and overheating of a space, such as overhangs, differential thermostats, and operable vents.
A true passive solar building includes proper orientation, collection, and distribution capability.
U.S. Department of Energy: Greening Federal Facilities - Building Placement and Orientation on a Site
BACKGROUND FACTS:
Building orientation can maximize opportunities for passive solar heating when needed, solar heat gain avoidance during cooling time, natural ventilation, and daylighting throughout the year. For example, southern exposure is the key physical orientation feature for passive solar energy in the northern hemisphere. Keep in mind that in the winter in the northern hemisphere, the sun comes up in the southeast and sets in the southwest. In the summer in the northern hemisphere, the sun comes up in the northeast and sets in the northwest. In the middle of the day in the summer, the sun is high in the sky overhead. In the middle of the day in the winter, the sun is low in the southern sky.
The basic considerations for optimizing the solar heating potential of a sunspace include the directional orientation and the angle of the glazing (glass or windows).
In general, a south-facing orientation within 30o east or west of true south will provide around 90% of the maximum static solar collection potential. The optimum directional orientation depends on site specific factors and on local landscape features such as trees, hills, or other buildings that may shade the sunspace during certain times of the day.
Rectangular buildings should be oriented with the long axis running east-west, so
the east and west walls receive less direct sun in the summer. In the winter, passive solar heat gain occurs on the south side of the building.
U.S. Department of Energy's Energy Savers: Sunspace Orientation and Glazing Angles
U.S. Department of Energy's Energy Efficiency and Renewable Energy Clearinghouse: Passive Solar Design for the Home
