Variable evaporator control for a gas dryer

A variable evaporator control method wherein gas at a first temperature is passed through first flow path in a heat exchanger having a second flow path through which a refrigerant at a second temperature lower than said first temperature is circulated to cool said gas to a third temperature, said method comprising:

• a. sensing a fourth temperature at a single location in said heat exchanger, said single location defined where both the second temperature and the third temperature are sensed, and at which said fourth temperature is representative of said third temperature when a gas load is above a certain level, and representative of said second temperature when said gas load is below said certain level;
• and
• b. adjusting said second temperature responsive to changes in said fourth temperature to generally maintain said fourth temperature at a desired value.