Heat pump systems have reverse-cycle technology meaning they can produce heating and cooling to your home. In cooling mode the heat pump creates cold water and pumps it to a fan coil unit. The fan coil unit transfers the chill from the water to air which flows through living areas via ducts in the ceiling.
Heat Pump – Heating
Heat pump units use a refrigerant to transfer heat from one place to another. In the heating cycle:
- Refrigerant enters the ground loop coils as a high pressure liquid
- The refrigerant passes through an expansion device which causes instant pressure and the temperature of the liquid to drop
- The liquid passes through the ground loops, absorbing heat from the surrounding earth, which causes refrigerant to boil off and change state into a vapour form.
- This vapour is now a useable substance to be re-compressed into a high pressure/high temperature vapour by the system’s compressor.
- The refrigerant is then used to heat your premises via a fan coil unit. Heat is transferred into the air passing over the copper finned coil and then distributed by ducting to heat your home.
Heat Pump – Cooling
In cooling mode the refrigeration cycle is reversed, meaning liquid refrigerant now enters the ducted fan coil unit via a refrigerant expansion device.
- As high pressure liquid passes through this device it creates a sudden pressure and temperature drop in the refrigerant. The heat from your premises now passes over the copper finned evaporator coil.
- Heat is absorbed into the refrigerant, creating cooler supply air and a change of state of this refrigerant.
- The heat absorbed into the refrigerant is now transferred into the ground loops via the systems compressor.
- Refrigerant passing through the ground loops is now dispensing heat into the earth causing a re-condensing effect in the refrigerant for the cycle to begin over.
Fan Coil Units
The coil receives hot or cold water from the heating/cooling source (e.g. heat pump) and removes heat from or adds heat to the air through heat transfer.
The fan coil units are controlled by a remotely wired thermostat.