There are two main geothermal heating & cooling systems available to Australian households - the revolutionary refrigerant-based EarthLinked® system (of which Energycore is the sole-distributor in Australia) and the more traditional water-loop based systems.
This page contrasts the two models and shows the significant advantages of the EarthLinked® system.
EarthLinked® Direct Exchange
Conventional Closed Loop Water Source
Uses no water
No Secondary water pump.
No additional energy to operate pump.
No pump
maintenance or replacement.
Uses water/glycol solution.
Must have
secondary water pump.
Stated energy costs are not
realistically included in efficiency ratings.
Earth Loop Differences
No groundwater contamination.
No Secondary or
intermediate heat exchanger.
No lost energy in exchange
process.
Refrigerant in ground coil actually goes through
a phase change process with high energy transfer.
Certified coefficiency of between 3.5 and over 5.0
Propylene Glycol must be added for pump lubricity and to
prevent freezing of pipes.
Refrigerant to water heat
exchanger required for system to function.
Lost energy in
exchange process.
Majority of phase change occurs in
secondary heat exchanger, low energy transfer.
Uses more refrigerant.
Requires avg. of 6 Lbs
per system ton.
R-22 refrigerant is safe by EPA
standards.
Mineral oil is used to lubricate
compressor.
No need for make up water due to leakage or
evaporation.
Uses less refrigerant.
Requires large amounts
of water plus 30% glycol solution to charge system.
When
combined with labour to install and purge loop field, actual
cost can be higher.
Make-up water required.
Less Invasive
If a leak occurs, the location is determined by
pressurizing system with mixture of Freon and Nitrogen and
simple refrigerant leak detectors.
Indoor location - Nitrogen purge while brazing leak area.
Pressure check, evacuate and recharge system.
Outdoor location - A shovel is used to uncover manifold
pit, (Installing Contractor, Sales Rep and Manufacturer have
records of manifold location) leak located. If leak is in
manifold joint, simply re-braze. If it is determined that the
leak is within the actual loop, many times the loop can be
isolated, system recharged and put back in operation without
drilling or excavation.
In either scenario if loop replacement is required, the
impacted land needing to be disturbed is 50-75% less.
More Invasive
First of all leakage occurs inherently due to the pump
and clamps sealing mechanisms. That is why a make up reservoir
is installed with this type of system. If the leak is not
excessive, most often you will be told to just add make-up
water. (Ongoing maintenance that you spent money to avoid.) If
an unacceptable leak occurs:
Indoor location - A visual inspection will determine
location. Many times the clamps used to secure the pipe with
begin to leak; a simple tightening may be all that is needed.
Outdoor location - Large areas of the yard will may have
to be dug up with a backhoe or similar machine to locate
source of leak. (Assuming accessibility is not an issue.)
Isolation of a loop is not an option. In either location, if
leak is in a fused joint then potentially the entire
water/glycol charge will have to be removed, pipe refused,
system refilled and purged.
Did you know?
'Energycore's Scientific Director Dr. Donald Payne has been invited to attend the Nobel Laureate's meeting in June 2008
