Heat Pumps Are Two Systems In One - Honeywell CT70 Wiring Manual

HEAT PUMPS ARE TWO SYSTEMS IN ONE

OUTDOORS
HEAT
TRANSFER
In mild weather, virtually all of the demand for heat in
buildings can be met by the heat pump compressor. This
First Stage process of moving heat indoors is very
economical. As the air becomes colder outside, the first
stage may be unable to deliver enough heat to maintain the
desired comfort level in the building.
OUTDOORS
HEAT
TRANSFER
During high heat demand, the thermostat will call for
additional Second Stage power from the auxiliary heat
system. This auxiliary heat is commonly electric resistance
heat and is two to three times more expensive to operate
than the compressor. If you have specific questions
concerning the operation of your heat pump, please contact
the equipment manufacturer.
OUTDOOR
AIR
OUTDOOR
AIR
MILD WEATHER
SEVERE WEATHER
INDOORS
AUXILIARY
HEATING
ELEMENT
OFF
INDOOR
AIR
M9069
INDOORS
AUXILIARY
HEATING
ELEMENT
ON
INDOOR
AIR
M9078
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