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Installation Manual Compac 6/8
1.1 Function Swimming pool heat pumps provide thermodynamic heating by means of a
vapour compression cycle, (similar to that employed in a conventional
refrigerator), in addition to acting as an active solar collector.
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.
This ratio will vary according to the temperature of the water and the ambient air.
THE HEAT PUMP CYCLE
HEATED
WATER TO
POOL
WATER
FROM POOL
HOT GAS
HEAT
EXCHANGER
CONDENSED
REFRIGERANT
HIGH PRESSURE SIDE
COMPRESSOR
EXPANSION
VALVE
LOW PRESSURE SIDE
COOL LIQUID
REFRIGERANT
AMBIENT
AIR
COOL GAS
EVAPORATOR
1
2
3
4
1. THE EVAPORATOR collects the heat from the
outside ambient air, pre-heated by the sun. In the
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 vaporises.This preheated vapour now
travels to -
2. THE COMPRESSOR
where it is compressed
and upgraded to a much
higher temperature. The
hot vapour now enters -
3. 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
-
4. THE EXPANSION DEVICE
and from there, now at normal
pressure, it is returned to the
evaporator and the cycle
starts again.
