Passive Solar

Passive solar design is actually an old concept. Ancient dwellings were constructed to take advantage of passive solar. The Anasazi Indians built homes facing south to allow the winter sun in while using overhangs to block direct sunlight in summer. The homes had thick walls and floors to help maintain even temperatures. The Greeks and other cultures also used design to best utilize the sun. Most of these concepts were forgotten when energy was cheap.

The basic concepts of solar design include:

• Orient the structure on an east-west axis.
• Place most windows on the south wall.
• Use overhangs or shading options to reduce summer sun on glass.
• Insulate well.
• Add mass, such as cement or stone.
• Provide proper ventilation.
• Place rooms where heat is most desired near the south wall.

Many forward thinking communities are incoroporating passive solar concepts into community planning. Simple design ideas can greatly reduce, or even eliminate, energy use. Some modern technologies, such as low-e glass, make passive solar even even more practical. A good book on the subject is 'The Solar House', by Daniel D. Chiras.

Many useful tools, such as a sun angle calculator and a sun chart program, can be found on the web for those wishing to explore solar design in detail. However, it doesn't have to be complicated to use simple and practical ideas to increase efficiency.