This Is How Your Heat Pump Works; Heat Pump Technology - IVT GreenlineC Manual To Installation, Commissioning And Maintenance

This is how your heat pump works:

Heat pump technology

The compressor, which is driven by an electric motor, forces the refrigerant into the heat pump
condenser as a gas at about 100°C. The gas and the water from the radiator system pass through the
condenser, which is a fully-welded stainless steel heat exchanger. When the hot gas is cooled by the
circulating water, it condenses (changes to liquid). As it does so, it provides energy for the heating
system or the hot water. After the condensor, the refrigerant, which is now in liquid form, continues
through a drying filter and a tank. The filter collects any moisture in the system and the tank is used as
an expansion vessel for the refrigerant to ensure there is always the correct amount in the condenser.
After the filter, the refrigerant passes through a sight glass. The sight glass is used to check the amount
of refrigerant in the system. In normal operation there should be no bubbles in the sight glass. How-
ever, bubbles may appear for short periods, mainly on rapid changes between hot water and radiator
operation and when the heat pump starts or stops.
After the sight glass the refrigerant goes to an expansion valve. The valve acts as a flow restrictor
between the high and low pressure sides of the system. The valve, which has a sensor (bulb) just
before the compressor, releases the right amount of liquid into the next heat exchanger, the evaporator.
In the evaporator, the liquid meets the circulating heat transfer fluid coming from the energy source in
the ground or bore hole. In this process, the liquid turns to gas (evaporates) under low pressure, which
uses heat. The heat is extracted from the the ground or bore hole free of charge.
After passing through the evaporator, the refrigerant is once more in the form of a gas (vapour). The
expansion valve sensor constantly checks that the evaporator is performing optimally, in order to use
as much free energy as possible. The gaseous refrigerant then goes to the suction side of the com-
pressor, where it is compressed again. This completes the refrigerant circuit.
To protect the heat pump, pressure switches are fitted on the high and low-pressure sides of the sys-
tem. These shut down the heat pump if the pressure in the system reaches an abnormal value. This is
dealt with in more detail in the section on troubleshooting.
Rock/Ground/Lake
Compressor
Pressure switch
Heat
transfer
fluid
pump
Expansion valve
Evaporator Filter
Sight glass
7
Heating system
Hot water
Immersion
heater
(not D)
Condenser
Pressure switch
3-way valve
(not D)
Heat
transfer
pump