The operating temperature differential of any self-contained thermostat depends on the following:
- The current flowing through the thermostat, also known as the amperage load
- The velocity of air over the thermostat
- The rate of temperature change that the thermostat is subjected to
- Whether the thermostat is operating heating or cooling equipment
Figure 1 and Figure 2 show the operating temperature differentials of these thermostats under various load conditions. The air velocity is 25 feet per minute (0.127 m/s) and the rate of temperature change is 6°F (3.3°C) per hour.
Note: For air velocities greater than 25 feet per minute or for rates of temperature change
less than 6°F per hour, the operating differentials are less than shown in the
graphs.
The T22T has a heating side and a cooling side. The upper line in the following graph illustrates the differential for the heating side of the T22T.
Figure 1. Heating operating differential for T22A and T22T
The upper line in the following graph illustrates the differential for the cooling side of the T22T.
Figure 2. Cooling operating differential for T22S, T22J, and T22T
