Passive Solar Energy Systems

Design and Orientation

• Many architects make use of building design concepts in a systematic manner to make structures more energy efficient by using solar energy. This includes placing buildings in positions that augment the sun's radiation to passively heat structures or reduce the need for cooling equipment. Many structures have open floor plans, which allow sunlight to flood through spaces. Some property owners build solar sun rooms with exposure to the equator onto new or existing structures. Taking advantage of landscape attributes, such as water, trees, rocks, hills and rock formations, also has a bearing on a building's passive solar performance.

Insulation

• Insulation forms a barrier between the interior and exterior. During cold weather, insulation prevents warn air from flowing to the outside. In hot weather, the insulation keeps warm air on the exterior and cool air inside. A well-insulated building helps maintain a consistent year-round temperature. The correct approach to installing insulation entails padding all building components by separating the interior from the exterior. Insulation comes in many types of materials, including loose fill, blanket, spray foam and rigid foam boards. The amount of insulation needed for optimal performance depends on the type of building component, such as floors, walls, ceiling or rafters. Follow the local building codes for the recommended insulating value for each building component.

Windows

• Windows go beyond functioning as decorative components of a home. Windows serve as solar collectors, which attract heat and light. They also provide fresh, cool air for ventilation. Architects should position windows (and doors) on the south side of buildings. A critical step involves correctly calculating the appropriate number of windows on the south elevation of a building to avoid the potential for overheating during the summer. In addition, limiting the number of windows placed on the north, east and west elevations insulates buildings against cold air in the winter. Installing shutters or drapery also offers effective methods for controlling heat gain during the summer months and nighttime heat loss throughout the winter.

Thermal Mass

• Thermal mass involves the use of certain materials to collect and store heat during the daylight hours. After sunset, the materials gradually release the heat. Large areas of the thermal mass have greater capacity to store heat. It also maintains a consistent temperature. Common forms of thermal mass include water, tile, brick, concrete and stone. With the properly calculated balance between solar collectors, such as windows and thermal storage mass, solar homes can maintain indoor temperatures ranging from 68 to 70 degrees.