Abstract: An apparatus for checking conditioning mode of a heat pump system includes: (a) a temperature sensing device coupled with the heat pump system at a sensing locus; (b) a comparing device coupled with the temperature sensing device and configured for comparing a first temperature sensed by the temperature sensing device at a first time with a second temperature sensed by the temperature sensing device at a second time to determine an extant conditioning mode; the extant conditioning mode being a first conditioning mode when the second temperature is greater than the first temperature; the extant conditioning mode being a second conditioning mode when the second temperature is less than the first temperature.

Abstract: A method for evaluating operation of a compression cooling system includes the steps of: (a) in no particular order: (1) measuring a first temperature of the refrigerant in a saturated state; and (2) measuring a second temperature of the refrigerant in a liquid state; and (b) calculating a difference between the first temperature and the second temperature to determine the extant amount of subcooling to which the refrigerant is subjected.