Passive solar design uses and anticipates the heat energy from the sun and its predictable movement to create efficient buildings that are warm in the winter and cool in the summer.
There are several building characteristics that are fairly common and work in conjunction with one another in passive solar design.
This passive solar house is facing the house, built with thermal mass, insulated and has an overhang that blocks the summer sun from entering the home.
These are typical commonalities within passive solar designed buildings:
Passive solar design works with regular pre-existing patterns.
The photo shows a time lapse photo over the duration of one year. The highest arc is the sun’s path on the summer solstice, while the lowest arc is the sun’s path on the winter solstice.
Passive solar homes typically have windows on the south side of the building. They have an overhang to block the high summer sun, while allowing the low winter sun to enter and warm the house.
This photo by Justin Quinnell shows the sun’s paths for one year.
The diagram below illustrates the same principles: how the sun travels differently on the summer and winter solstices.
Diagram showing the sun on the summer and winter solstice at Los Alamos, New Mexico, Courtesy of the Los Alamos National Laboratory
On June 21st at 9am, the sun is at a 49 degree angle from the ground and travels a high arc across the summer sky. On December 21st on the winter solstice, at 9am, the sun has risen to a 17 degree angle and travels a short, low arc across the winter sky before setting. In order to benefit from the energy given by the sun, the building must face as close as possible to true south.
‘High Street’ building companies ought to be using these principles in their buildings. Local construction workers need to be re-educated too. And we always see luxury buildings so far beyond the reach of your everyday home owner/renter. The methods and materials need to be available to everyone so that even the smallest house or flat can be built in this way.