This page contrasts the two models and shows the significant advantages of the EarthLinked® system.

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.

• 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 co-efficiency 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 0.6kg per system kWth.
• R407 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.