Geothermal Exchange Advice

How does a Ground Source Heat Pump work?

The basic principles of a closed-loop GSHP system begins with the absorption of heat from the ground heat source. This is typically an array of pipes buried underground horizontally, vertically in a bore-hole, or even laid in a lake.

Heat absorption is achieved by circulating water mixed with antifreeze (Glycol) through a closed collector pipework system. The temperature of the earth at one metre below ground level remains fairly consistent between approximately 6 – 12ºC throughout the year depending on geographical location and soil type. Contrary to popular belief this is stored solar energy, energy from rainfall and (in some circumstances) energy from migrating groundwater, not geothermal exchange heat from the centre of the earth.

The stages of the Ground Source Heat Pump

  1. The energy in the form of heat is absorbed from the heat source (rock, ground or lake) through a closed collector system containing water mixed with vegetable-based antifreeze.
  2. The collector fluid then transfers this energy to the refrigerant in the heat pump’s evaporator heat exchanger.
  3. The refrigerant vaporises and is then compressed in the compressor which is where most of the electricity is consumed. When a gas is compressed its temperature increases to around 50°C (this is the core scientific principle behind the gas compression cycle).
  4. The refrigerant, with its increased temperature, enters the condenser heat exchanger where it transfers its energy to the heat medium circuit. This then provides spatial heating to the wet radiator or underfloor heating circuits, the hot water cylinder or a combination of heat emitters…


Image source: Geotec

  • Do you want to know more? Read some of our articles here.
  • Do you want to see some of our projects? Click here.
  • Do you want to contact us? click here.



Geothermal Exchange Heating and Cooling Solutions

Commercial HVAC

Stands for heating, ventilation and air conditioning. This system provides heating and cooling to commercial buildings.

Residential Solutions

Australia’s leading Residential Builders and Architects, successfully completing complex and challenging projects on time and beyond expectation.

Geothermal Exchange

The basic principles of a closed-loop GSHP system begins with the absorption of heat from the ground heat source.

Our Trusted Partners

We engaged CWL for the geothermal exchange and HVAC works on our unique project in Bellevue Hill and were selected based on pricing and their previous experience. It turned out to be the best choice in subcontractors we made for the whole project. Their professionalism, work ethic, expertise and willing to help wherever needed made a highly complex services installation that much easier, and more efficient than expected. I’d like to personally thank James and the site team who put the extra effort in at all times to get our project over the line with remarkable results. Highly recommended Subcontractors and mechanical consultants.
- Theo Elphick, Site Manager, Built
A culture of striving for excellence combined with motivated and dedicated staff is what defines CWL Group. Their workmanship is second to none and it is obvious that all of the staff care about what they do. Commitments are met and exceeded and there are no problems that can’t be resolved. I’m looking forward to working with Clayton and his team in the future and have no hesitation in recommending them to anyone.
- Mick Carroll, Bellevarde Constructions
The team from CWL Group are very reliable, responsive and efficient in their work. They go above and beyond to make sure the job is completed at its highest standard. The knowledge of the guys is exceptional. I would recommend the CWL Group team every time!
- Annemarie Rodrigo, Bellevue Hill House Keeper
I want to thank CWL Group for the outstanding work in installing our hydronic heating system. I have worked with many plumbers over the years and I have never seen such a high standard of workmanship. They came in on time and on budget. I cannot recommend the team from CWL Group highly enough.
- Robert & Roberta Cook, Blue Mountains

Service that goes Above and Beyond... and Below.

Contact us