This Is How Your Heat Pump Works; Heat Pump Technology - IVT Greenline D14 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 heat transfer fluid 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 condenser, the refrigerant, which is now in liquid form,
continues through a drying filter and a tank. The filtercollects any moisture in the system and the tank
is used as an expansion vessel for the heat transfer fluid to ensure there is always the correct amount
in the condenser.
After the filter, the heat transfer fluid passes through a sight glass. The sight glass is used to check the
amount of heat transfer fluid in the system. In normal operation there should be no bubbles in the
sight glass. However, 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 heat transfer fluid 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 outside air free of charge.
After passing through the evaporator, the heat transfer fluid is once more in the form of a gas (va-
pour). 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 compressor, where it is compressed again. This completes the heat transfer fluid circuit.
Pressure switches are fitted on the high and low-pressure sides of the system to protect the heat
pump. 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
Heat transfer
fluid pump
Compressor max
Pressure switch
Expansion valve
Evaporator Sight Filter
glass
Heating
system
Hot water
Electric water heater
(E series only)
Pressure Condenser
switch
3-way valve
(E series only)
Heat
carrier pump