The Heat Pump Cycle - Calorex Pro-Pac Series Owners & Installation Manual

THE HEAT PUMP CYCLE

2. THE COMPRESSOR where it is compressed and
upgraded to a much higher temperature. The hot
vapour now enters –
WATER OUT
WATER IN
3. THE CONDENSER where it is surrounded by the
pool water. The heat is given up to the cooler pool
water and the now cold refrigerant returns to its former
liquid state but still under high pressure from the
compressor.
This pressure is released by passing the liquid through –
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.
SD566250 ISSUE 35
2
COMPRESSOR
HOT GAS
3
HEAT
EXCHANGER
EVAPORATOR
CONDENSED
REFRIGERANT
EXPANSION
VALVE
4
HIGH PRESSURE SIDE
4. THE EXPANSION DEVICE and from there, now at normal
pressure, it is returned to the evaporator and the cycle starts
again.
Note that during the cooling cycle this process is reversed
1. THE EVAPORATOR collects the heat from the
outside ambient air, pre-heated by the sun. In the
Calorex swimming pool heat pumps, high volumes of
outside air are drawn into the unit by the fan 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 preheated vapour now travels to –
COOL GAS
1
COLD LIQUID
COLD LIQUID
REFRIGERANT
REFRIGERANT
LOW PRESSURE SIDE
AMBIENT
AIR
5