But about 15 years ago, a Swiss architect developed and patented a wall system that provides passive solar heat gain for new homes and buildings. (realtormag.realtor.org)
A 4.2 m x 2.1 m glass sliding door provides passive solar heating. (passivehouseplus.ie)
I live in the northeast and can cheaply grow year round by using passive solar heating. (tinyhousebuild.com)