Method and apparatus for controlling supplemental heat in a heat pump system

摘要

A method and apparatus for controlling supplemental heat added to the air stream passing from an indoor coil to an air supply duct of a heat pump system, the heat pump system being of the type that includes an indoor thermostat having a first set point for initiating heat supplied by the indoor coil and a second set point for initiating additional heat supplied by supplemental heating means. The supplemental heating elements include an adjustable output heating element for heating air passing from the indoor coil to the air supply duct. The coil discharge temperature of the air stream heated by the indoor coil is determined at a position between the indoor coil and the supplemental heating means. The adjustable output heating element is selectively energized in response to the coil discharge temperature, independent of the second set point of the indoor thermostat.