The manufacturer should be consulted to determine the combined efficiency. Most major manufacturers' product lines are included in this directory. This equipment provides variable speeds of operation to optimize performance and efficiency. Heat pumps utilizing multi-speed components will typically start in the first stage or low speed. If comfort levels or control settings cannot be satisfied with the first stage, the second stage or high speed will activate.
Some heat pump systems have more than two stages or speeds of operation.
Larger Coil Surface Areas - Large surface coils provide maximum heat transfer efficiency. Time Delays - Time delays vary the on and off cycles of compressors, motors, and supplemental heat packages. Expansion Valves - Expansion valves control the flow of refrigerant in proportion to the load on the evaporator. Compared with other types of fixed metering devices, expansion valves are able to exercise control over a much wider range of operating conditions. Dual fuel heat pump systems are supplemented by a fossil fuel furnace or boiler instead of the traditional electric resistance coils.