Passive Solar Heating – Using solar energy to heat and light buildings

The south side of a building always receives the most sunlight. Therefore, buildings designed for passive solar heating usually have large, south-facing windows. Materials that absorb and store the sun’s heat can be built into the sunlit floors and walls. The floors and walls will then heat up during the day and slowly release heat at night, when the heat is needed most. This passive solar design feature is called direct gain.

The Zion National Park Visitor Center incorporates passive solar design features, including clerestory windows for daylighting and Trombe walls that absorb heat during the day and give off heat at night.

Many of the passive solar heating design features also provide daylighting. Daylighting is simply the use of natural sunlight to brighten up a building’s interior. To lighten up north-facing rooms and upper levels, a clerestory—a row of windows near the peak of the roof—is often used along with an open floor plan inside that allows the light to bounce throughout the building.

In the United States, heating, ventilation, and air conditioning (HVAC) systems account for over 25 percent (4.75 EJ) of the energy used in commercial buildings and nearly half (10.1 EJ) of the energy used in residential buildings.