Определение thermal mass в Английский Язык Английский Язык словарь
Thermal mass, in the most general sense, is any mass that absorbs and holds heat. In the architectural sense, it is any mass that absorbs and stores heat during sunny periods when the heat is not desirable in the living space of a building, and then releases the heat during overcast periods or during the night, when the heat is desirable. The same can be said for not absorbing heat during hot periods of weather