What is Passive Solar Design?

There are many methods for maintaining comfortable temperatures in a building, including the use of fossil fuels and electricity to produce heat. Many times, heating systems require mechanical or electrical systems to function properly. Passive solar design, which might also be known as passive solar building design or climatic design, is a method of heating and cooling a building using natural processes. The goal of passive solar design is to manage this solar heat throughout the year, cooling the interior of a building in the summer and heating it in the winter.

An important aspect of passive solar design is the configuration of a building based on the local climate. The path of the sun on any given day is different for each location on Earth, so a building usually can be designed to exploit this position. Considering the yearly path of the sun is an important step in passive solar design. Other important steps might include weatherization of openings, energy efficient windows and special insulation made to store and redistribute heat based on specific local weather patterns. Though the specific design changes based on local condition, most passive solar designs include a few features.

Generally, an effective passive solar design will include some sort of heat collector, such as large sun-facing windows and dark-colored exterior materials. The heat can be absorbed or collected, and the design can include some sort of storage medium. This is usually called the thermal mass, and it allows the heat to be distributed in whatever way necessary. Important elements in an effective passive solar design might also include ways to control solar heat, such as with certain room and ceiling sizes; exterior overhangs to protect windows from the summer sun; and vents designed to make use of natural heat processes, such as conduction, convection and radiation.

Many elements in a passive solar design can work for both heating and cooling purposes. For instance, passive solar heating systems might use windows that face the sun. This allows light and heat to enter a space where it might be held or redistributed. The side of the building facing the sun might also be made with dark materials to help the building absorb heat and store it for later distribution. When a building must be cooled, however, passive solar design elements might include vents that take advantage of natural wind flow or specially designed intakes meant to accelerate incoming wind speeds.