What is a passive solar designed house?

A passive solar designed house needs to do two things. It needs to be able to collect and store free energy from the sun in winter, and in summer keep the sun’s heat energy out. A passive solar home will do this with the correct orientation to the sun, correctly designed eaves overhangs and careful placement of windows. In winter, the sun’s energy is allowed to enter the house throughout ‘day’ areas and warm surfaces, the internal air space and the occupants whilst also heating the thermal mass of the internal parts of the house. Thermal mass is a material’s ability to absorb and hold heat. The heat stored slowly radiates back into the house after the winter sun has set. Conversely, by blocking the summer sun from warming the thermal mass in summer, the material and inside environment stays cooler, which assists in comfort levels before artificial cooling is sought. With these basic principles of correct shading, combined with careful placement of windows for natural cross ventilation, effective passive cooling can occur in summer nights to also reduce overall temperatures.