Passive Solar Heating and Cooling

Passive solar heating captures and stores the sun's energy without mechanical systems. The three key components are: collection (south-facing glazing that admits low-angle winter sun), absorption (thermal mass—concrete floors, brick walls, or water containers—that absorbs heat during the day), and distribution (the natural processes of radiation, convection, and conduction that move stored heat into occupied spaces at night). A well-designed passive solar home can meet 50-70% of its heating needs in cold, sunny climates like Colorado or southern Germany. The concept dates to ancient Greek and Roman urban planning, which oriented streets to capture winter sun.