For ASHRAE’s chart, only thermodynamic wet-bulb T* lines
are shown. Since the dry-bulb and the thermodynamic wet-bulb temperatures coincide with each
other on the saturation curve, one end of the T* line is determined. The other end of the T* line can
be plotted on the w line where w 0. Let the state point of the other end of the T* line be represented
by 1. Then, from Eq. (2.39), at w1 0