Heat pumps use electrical energy and take low grade heat energy from the outdoor air, to heat refrigerant which in turn heats water for domestic use and space heating. The efficiency of a heat pump is known as the Coefficient of Performance or CoP. This is a ratio of the heat delivered to power consumed. The operation of a heat pump is similar to a refrigerator – but in reverse. This process is known as the vapour compression cycle.

At the beginning of the first phase the refrigerant is a cold low pressure liquid.

1. The refrigerant passes into the evaporator and heat energy from the outside air passes over the evaporator causing the refrigerant to increase in pressure and change to a warm vapour.

2. This warm vapour then enters the compressor where its temperature increases as a result of the compression process and turns into a hot gas.

3. The hot refrigerant gas is then condensed as it passes across one side of a plate heat exchanger. The heat is transferred to the cooler side (water side) of the heat exchanger, and this is transferred via the primary water circuit to heat up the water tank inside the property. As the temperature of the refrigerant decreases the state changes from a gas back to a cool vapour.

4. Despite dropping in temperature, the cool vapour still has a high pressure and to reduce this pressure the vapour passes through an expansion valve. This causes the pressure to drop and the temperature lowers, returning the refrigerant to its initial state of cool low pressure liquid.

This process is repeated It is only the refrigerant that passes through this cycle; the water is heated as it travels through the plate heat exchanger. The heat energy from the refrigerant passes through the plate heat exchanger to the cooler water which increases in temperature. This heated water enters the home heating circuit and can also be used to provide domestic hot water via a hot water cylinder.

To learn more about the Ecodan Heat Pump range download the brochure.