A passive solar building is a structure built using solar energy design techniques. This field of design takes advantage of the natural heat energy and light provided by the sun. In cold climate zones, a passive solar building will be designed to maximize sun exposure for free, natural heating. In warmer climate zones, passive solar buildings are designed to minimize heat gain from the sun to keep temperatures inside at a comfortable level. Passive solar design does not necessarily require solar panels or other active solar components.
Effective heating and cooling typically are the primary design focus of any passive solar building. These buildings feature large windows that are positioned to maximize sun exposure in cooler climates. The floors and walls of the building are often made from special materials, such as concrete or brick, which naturally absorb and store this solar heat. Once the sun goes down, this heat energy radiates through the home to provide free heating.
In hot climate zones, a passive solar building is often oriented to minimize sun exposure during the hottest parts of the day. This may include using special window glazing or reflective roofing to keep sunlight and heat out of the building. It also includes strategic use of landscaping and trees to provide cool shade and block the sun's rays. In both hot and cold climate zones, effective insulation and weatherstripping techniques play a major role in passive solar design success.
A passive solar building may also include features such as solar water heaters or solar cookers. Passive solar water heating utilizes special tanks or pipes installed along the roof to take advantage of heat energy from the sun. The water then flows to sinks, showers, and other fixtures within the home. Solar cookers resemble small boxes lined with solar panels. The panels absorb solar energy to naturally heat the food inside without the use of electricity.
Natural lighting also plays an important role in passive solar design. Windows and skylights are used to allow light into the home and reduce the need for electric lighting. Blinds may be added to keep out the sun during the afternoon hours to reduce solar heat gain.
A passive solar building offers a number of advantages to occupants and owners. These structures require smaller heating and cooling systems than traditional structures, and some may require no furnace or air conditioner at all. By reducing the need for electricity and fossil fuels, passive solar design allows homeowners to maximize energy efficiency and keep costs low. Efficient building design helps to protect the environment by lowering pollution rates and conserving limited resources.