An exterior solar-glazed thermal storage wall absorbs sunlight (heat) in winter, conducting heat through the wall and releasing it into an adjacent space at night.
A Thermal Storage Wall is a mass wall, usually masonry, located directly behind solar glazing (facing the equator).
Size the wall and solar glazing area as a percentage of the floor area to be heated:
- 30% at 28º – 40º latitude
- 40% at 44º – 56º latitude
- 20% at 28º – 40º latitude
- 30% at 44º – 56º latitude
Make the exterior wall surface a dark color, and make the thickness of the wall:
- 30 – 46 cm (12-18 in) for concrete
- 25 – 36 cm (10-14 in) for brick
- 20 – 30 cm (8-12 in) for adobe
*Cold = Winter temp. -6.7ºC to -1.1ºC (20ºF to 30º F); **Temperate = Winter temp. 2.2ºC to 7.2ºC (35ºF to 45º F). When there is a useable space between wall and glazing, and a convective connection to adjacent spaces, the wall can be a medium color. Recommendations are for skin-load dominated buildings.