How The Heat Pump Works - Calorex AW631 Owners & Installation Manual

The CALOREX Swimming Pool Heat Pump provides thermodynamic heating by means of a vapour
compression cycle (similar to that employed in a conventional refrigerator), in addition to operating as an active
solar collector.
The EVAPORATOR collects heat from
the outside ambient air, pre-heated by the
sun. With Calorex, swimming pool heat
pumps high volumes of outside air are
drawn into the unit by the fan and expelled
through the evaporator fins. The evaporator
has liquid refrigerant passing through it,
which is at a considerably lower
temperature than the ambient air, therefore
the air gives up its heat to the refrigerant,
which then vaporizes.
This pre-heated vapour now travels to-
Outside Air
The EXPANSION DEVICE
and from there, now at low
pressure, it is returned to the
evaporator and the cycle starts
again.
Coefficient of Performance
The efficiency of a Heat Pump is usually called its 'Coefficient of Performance' - (C.O.P.) which is
simply a ratio of heat output to energy input, both being expressed in kW. Thus a Heat Pump
absorbing 1 kW of electricity, collecting 4 kW of energy from the air, and delivering 5 kW of heat to
the pool water is said to have a C.O.P. of 5:1.
Naturally this ratio will vary according to the temperature of the water and the ambient air.

HOW THE HEAT PUMP WORKS

Compressor
Cooled Air Exhaust
Evaporator
(Heat Collector)
Expansion
Swimming
Pool
Pool Filter
Condenser Heat Tranfered
to Pool Water
Device
The CONDENSER where it is
surrounded by the pool water. The heat
is given up to the cooler pool water and
the now cooler refrigerant returns to its
former liquid state but still under high
pressure from the compressor.
This pressure is released by passing
the liquid through -
Page 4
The COMPRESSOR
where it is compressed and
upgraded to a much higher
temperature.
The hot vapour now enters -
Pool Water
Pump
Pool Water