Passive Solar Heating

Correct Orientation

 passive solar windows (glazing) must face true south or within 30 degrees of true south and not be shaded by other buildings or trees from 9:00am to 3:00pm during the heating season.

Find true South

Notice that the solar north-south is different from magnetic north-south. The short axis of your home should orient toward solar north-south.

Thermal Mass

tile covered floors, masonry walls, and water filled containers are used to store heat for nighttime heating.

Control Structures

overhangs or controlled openings that block the sunlight and prevent the heated air from entering the house during the summer.

Heat Distribution (optional)

solar heated air is distributed using natural air movement from the passive solar heating systems to actively used rooms. Active mechanical systems such as fans are also commonly used in passive solar designs.                                                                       

Direct Gain Systems

the most common and the simplest design. These systems use south facing glass windows connected directly to living spaces with thermal mass in the form of concrete or masonry walls or floors to capture and store the sun's energy.                                                                                               

Passive Solar Sunspaces

these systems utilize rooms independent of the home's heating and cooling system to capture the sun's energy. The sunspaces are comfortable during much of the year, but are not intended to be living spaces for the home.                                                                                                            

Thermal Storage Walls

also known as Trombe walls, this design requires construction of two exterior walls - one made of south-facing glass, and one made of concrete to act as a thermal storage wall. The wall stores the solar heat gained through the glass, and radiates into the living area.                                                                         

Solar Air Collectors

solar air collectors operate on a similar principle as thermal storage walls, though they generally cost less since the thermal mass is reduced. They work by ventilating the warm air in the space connected to the south facing glass into the home through vents in the top and bottom of the wall.