“…Habitable space. This is the room space [1, [9][10][11][12][13] in which the temperature is to be controlled. Although the air temperature of a room varies continuously from point to point throughout a room, and therefore is a function of both space and time, it has been found that under forced air operating conditions the temperature in a domestic enclosure can be approximated, for most engineering purposes, by a three region model as will be shown in a subsequent paper.…”