Average temperature differentials on an air conditioner thermostat, the difference between the temperatures at which the air conditioner turns off and turns on, vary by operating conditions. Temperature differentials that range between 0.8 degrees Fahrenheit and 2 degrees Fahrenheit balance the conflicting goals of comfort and efficiency.
Differentials closer to zero degrees offer more comfort but force the air conditioner to cycle on frequently. Larger differentials are better for the equipment, but humans perceive anything over a 2-degree differential as uncomfortable.
Most thermostats have temperature differentials defined in factory settings. Programmable thermostats allow changes to the differential from 1 to 3 degrees. Mechanical thermostats are especially susceptible to the phenomenon known as "droop," which is a lowered differential during high use caused when cooling equipment generates heat. Droop leads to continuous cycling and stress on the air conditioner.