From NCMA eNews
July 11, 2019
Thermal mass of concrete masonry absorbs heat, which is then slowly released to keep interior temperatures at a comfortable level. Using the thermal mass of concrete masonry as a heating system is an application of Passive Solar Design. Thermal mass reduces the reliance on mechanical heating and cooling and thus lessens the energy cost.
For more information, see TEK 6-5A Passive Solar Design.