Calorex Pro-Pac PPT45EHC - Heat Pump Operation; The Heat Pump Cycle

COLD LIQUID
REFRIGERANT
3
4
COOL GAS
AMBIENT
AIR
1
2
COMPRESSOR
EVAPORATOR
HIGH PRESSURE SIDE
CONDENSED
REFRIGERANT
WATER IN
HOT GAS
WATER OUT
HEAT
EXCHANGER
LOW PRESSURE SIDE
EXPANSION
VALVE
COLD LIQUID
REFRIGERANT
THE HEAT PUMP CYCLE
Coecient of Performance
The eciency of a heat pump is usually called its ‘Coecient of
Performance’ – (C.O.P.) which is simply a ratio of heat output to energy
input, bo being expressed in kW. Thus a heat pump absorbing 1 kW
of electricity, collecting 4 kW of energy from e air, and delivering
5 kW of heat to e pool water is said to have a C.O.P. of 5:1.
Naturally, is ratio will vary according to e temperature of e water
and e ambient air.
1. THE EVAPORATOR collects e heat from e
outside ambient air, pre-heated by e sun. In e
Calorex swimming pool heat pumps, high volumes of
outside air are drawn into e unit by e fan expelled
rough e evaporator fins. The evaporator has liquid
refrigerant passing rough it which is at a considerably
lower temperature an e ambient air. Therefore
e air gives up its heat to e refrigerant which en
vaporizes. 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 e
pool water. The heat is given up to e cooler pool
water and e now cold refrigerant returns to its former
liquid state but still under high pressure from e
compressor.
This pressure is released by passing e liquid rough –
4. THE EXPANSION DEVICE and from ere, now at normal
pressure, it is returned to e evaporator and e cycle starts
again.
Note at during e cooling cycle is process is reversed
5
SD566250 ISSUE 35