Passive Solar Heating

Passive Solar Heating presents the most cost effective means of providing heat to buildings. Generally, the amount of solar energy that falls on the roof of a house is more than the total energy consumed within the house. Passive solar applications, when included in initial building design, adds little or nothing to the cost of a building, yet has the effect of realizing a reduction in operational costs and reduced equipment demand. It is reliable, mechanically simple, and is a viable asset to a home. The following are rules of thumb and an explanation of the essentials of passive solar design.

The mechanism of heating and cooling equipment is usually referred to as a system. A building is designed (home, apartment house, etc.) and a heating/cooling system using forced air equipment with air ducts; radiant floors using hot water; etc., is specifically designed for it. In passive building designs the system is integrated into the building elements and materials - the windows, walls, floors, and roof are used as the heat collecting, storing, releasing, and distributing system. These very same elements are also a major element in passive cooling design but in a very different manner. It should be understood that passive solar design does not necessarily mean the elimination of standard mechanical systems, although recent designs coupled high efficiency back-up heating systems greatly reduce the size of the traditional heating systems and reduce the amount of non-renewable fuels needed to maintain comfortable indoor temperatures, even in the coldest climates.

The preceding explanations show that two elements must be present in all passive solar heating designs: a south facing exposure of transparent material (glass, plastic) to allow solar energy to enter; and a material to absorb and store the heat (or cool) for later use. With these two basic elements in mind a number of approaches to designing a passive solar heated structure are available. Passive cooling is discussed elsewhere in this tutorial.