Local Knowledge About Thermal Mass And Heat Storage

Almost all passive solar systems work in conjunction with thermal mass, or materials with a high capacity for absorbing and storing heat (e.g., brick, concrete masonry, concrete slab, tile, adobe, water). Thermal mass can be incorporated into a building design as floors, interior walls, fireplaces, etc. The sun does not need to hit these surfaces directly to store the heat, nor do these surfaces necessarily need to be a dark color. Generally, the higher the density of the material, the better. Effective materials for floors include painted, colored or acid-etched concrete, brick, quarry tile, and dark ceramic tile. When more mass is required, interior walls or interior masonry fireplaces can be incorporated into the design. From an energy standpoint, it would be difficult to add too much thermal mass in a house. But thermal mass has a cost, and so adding too much mass just for thermal storage purposes can be unnecessarily expensive. As with all aspects of solar design planning, it is necessary to achieve a workable balance.