What is Passive Solar Heating?


Passive solar heating, also known as passive solar design, takes advantage of a building’s architectural design to store and distribute solar energy in the form of heat. These buildings distribute heat throughout the structure in the winter months but not in the warmer summer months. By reducing the amount of energy needed to heat the building, passive solar heating can put a big dent in a building’s energy use in the winter. Heating and cooling accounts for nearly half of all energy use in a typical home. 

There are five main components that make up passive solar heating systems:

  • Collector— The collector is usually a large window that faces true south within 30 degrees so that it can take in sunlight between the hours of 9 AM and 3 PM during the colder months.
  • Absorber— The absorber is the hard dark surface that absorbs sunlight and converts it to heat energy.
  • Thermal mass—The purpose of the thermal mass is to absorb the heat and is the material beneath the absorber.
  • Distribution — The distribution process circulates the heat stored in the thermal mass throughout the building.
  • Control—To regulate the temperature of a building, each passive solar heating system includes roof overhangs used for shading purposes, as well as differential thermostats, operable vents, and dampers that either allow or restrict heat flow.  All of these help control the temperature of the buildings.

Because they are often implemented during the initial stages of construction, passive solar heating systems pay for themselves very quickly through energy savings. Passive heating systems are also integrated into the building design and require minimal maintenance.

Licensed Photo by Darren Greenwood