What is Direct Exchange (DX) geothermal heating and air conditioning and how does it work?
Geothermal is an alternative energy source that takes the heat from the earth, where the temperature is a constant 15 degrees, and uses that energy to heat and cool your home or business.
Geothermal heat pumps are suitable for:
- Commercial buildings
- Small to large homes
- Existing and new homes
- Swimming pools
- Bulk hot water
- Horticulture and farming.
On this page we’ve done our best to explain in simple terms how the technology works. If you would rather talk to us about how the technology can work for you, please Contact Us.
AusGeothermal Heat Pump – How this works for heating your home or business
AusGeothermal heat pump units are a direct exchange refrigeration system using R410A 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.
While this is happening, refrigerant in the copper finned coil is changing state and condensing from a high pressure vapour to a high pressure/low temperature liquid. This liquid is re-directed to the ground coils to begin the cycle over.
AusGeothermal Heat Pump – How this works in cooling your home or business
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.
Geothermal hot water production – How this works
By using AusGeothermal heat pumps hot water can be produced via a plate heat exchanger, which is mounted in the unit.
The heat exchanger works by transferring heat from discharge refrigerant super heated by the system’s compressor through a set of copper and stainless steel plates. Water passes over the opposite side of these plates absorbing heat and re-circulating back to your sanitary hot water cylinder or via hydronic heating.
When the system is being used for heating or cooling, HOT WATER CAN BE PRODUCED FOR FREE.
Ground loops can be arranged in different configurations, to suit your application.
Horizontal trenching is the most cost effective way to install ground loops. Trenches that are 450-600 mms wide and normally 30 metres long can be installed at various depths to suit ground conditions.
Where space is an issue ground loops can be installed into 100mm bore holes that are 30 metres long. Bore holes are then filled with a grouting mixture to transfer heat into the earth.
Maintenance of AusGeothermal systems
AusGeothermal systems require minimum maintenance due to the design of the DX geothermal system.
No top up water or glycol is used in our system, which means high efficiency and user-friendly design.
Ducted systems require air filters to be cleaned when necessary. We provide instructions so that you can easily carry this out yourself.