an Entity references as follows:
A thermal mass refrigerator is a refrigerator that is foreseen with thermal mass as well as insulation to decrease the energy use of the refrigerator. A particularly popular thermal mass refrigerator was conceived by Michael Reynolds and detailed in the book "Earthship Volume 3". This refrigerator was a DIY refrigerator designed around a (Sun-Frost) DC refrigeration unit run on P.V. panels.