Passive solar homes are designed to use radiant energy from the sun for home heating. The walls, windows and floors of the home aid in the collection, storage and distribution of solar energy. Passive solar homes are different from homes with active solar heating systems that use mechanical and electrical devices, including motors, pumps and fans. In the passive solar home, no devices are required for solar heating.
Passive solar homes incorporate these five components in their design:
1.The aperture (or collector) is a large glass window that brings sunlight into the home. Ideally, the aperture receives sunlight for at least six hours per day and faces within 30 degrees of true south.
2.The absorber is a solid surface (such as a wall or floor) or water container that is positioned in the path of sunlight that enters the aperture. The heat from the sunlight is absorbed by surface of the absorber. Solid surfaces that are used as absorbers are usually dark because dark colors absorb more heat.
3.The thermal mass is the part of the absorber that retains and stores heat. For example, its the part of the wall below the surface.
4.Distribution is how heat moves from the absorber to different parts of the house. Natural heat transfer mechanisms such as conduction (the movement of heat from warmer areas to colder) and convection (the circulation of heat in gases and liquids) are used to distribute the heat.
5.Control mechanisms allow a homeowner to limit heat collection to only the colder months in the year. During the summer, heat collection is minimized. For example, a window awning can be used to shade an aperture window during the summer months.
Designing Passive Solar Homes
Passive solar design can be built into a new home and older homes can be retrofitted to use this form of energy. Passive solar design can be implemented in different degrees, ranging from a passive system that provides most of a homes heat to one south-facing window that heats a single room.
When designing a passive solar home, the climate of the homes location must be taken into account. Windows must be located to capture the maximum amount of sun per day during the colder months. Glazing is often applied to windows to increase the amount of heat absorbed. Some passive solar homes make use of a Trombe wall, which is a masonry wall between 8 and 16 inches thick that is placed between the aperture window and the homes living space.
Landscaping for Passive Solar Homes
The landscaping around passive solar homes can reduce their heating and cooling requirements, contributing to the effectiveness of the passive solar system. Trees and shrubs planted around the home can serve as windbreaks, reducing wind chill. They can also trap blowing snow and prevent it from settling near the homes exterior walls. Trees will also provide shade during warm summer months and reduce a homes cooling requirements.
