HP Building Solutions | Frequently Asked Questions about Geothermal Systems



*Where can a geo thermal system be installed?* Geo thermal systems can be installed in either new construction or a pre-existing structure. What sets EarthLinked® apart from air source heat pumps? By using the constant and favorable temperature of the earth as its heat source, 75% of the heat delivered to the building by EarthLinked® is renewable energy, therefore efficiency is greatly improved. Mechanical simplicity and the constant earth temperature assure longer equipment life and less maintenance. *What sets EarthLinked® apart from other geo systems?* EarthLinked® systems use copper earth loops to directly exchange heat with the earth, thus eliminating the water circulating loop and intermediate heat exchanger. Installation, operating and maintenance costs are thereby reduced. Because of its size, EarthLinked® can be installed in smaller yard space than other systems.
*Why is EarthLinked® more efficient than other geothermal systems?* EarthLinked® eliminates the intermediate heat transfer required by water-based systems. Its direct heat transfer method does not require the circulating pump found in water-based systems. The system is also inherently more efficient because of ECR's modulating refrigerant flow controls. *How is the earth loop system installed?* DIRECT AXXESS® Earth Loops can be installed horizontally in pits or trenches using excavators or trenchers, as well as vertically or diagonally using small bore drilling equipment. *How long does it take to install the earth loops?* Loops for a 3-ton system in pits and trenches can be installed in a single day. Loops using vertical and diagonal bores can be installed in two days.
What special training is required for installation? System start-up does not require a purging cart, the addition of antifreeze, or other tasks associated with water loop systems. On the refrigerant side, factory-assembled earth loops are soldered to pre-fabricated manifolds, and visual indicators assist in system charging (no charging charts needed). Thus, little special training is required for installation. How long have EarthLinked® systems been operating? In 1980, ECR began research and development of EarthLinked® systems. In 1985, field demonstrations began for six electric utilities from Florida to Michigan. Marketing commenced in 1992. Can I replace an existing air source heat pump with EarthLinked®? Yes. Existing ducting and air handlers can be used with minor modifications and the addition of the earth loops and compressor unit. What effect does EarthLinked® have on the environment? U.S. EPA and DOE have determined that ground source heat pumps have the lowest environmental impact of all heating systems and they reduce energy consumption and corresponding emissions up to 72% when compared to electric heat strips and standard air conditioning. The refrigerant used by EarthLinked® is not toxic, and is the same as that currently used by a majority of the HVAC industry.

How long will the earth loops last? Copper is one of the few metals that exist naturally as an element in the earth. A noble metal, it is essentially immune to corrosion in most underground environments because of the protective film that forms naturally on its surface. In rare exceptions where pH readings exceed safe levels, cathodic protection for the in-ground copper is offered by ECR. With some installations dating back to 1980, ECR has never experienced a field failure of the copper pipe due to corrosion or mechanical damage. *How do the earth loops work?* The standard compressor circulates refrigerant through the earth loops (with sufficient velocity to transport the lubricating oil through the system) while it is heating in the winter or reversing the flow for cooling in the summer. Its patented refrigerant flow controls assure a flooded evaporator condition and full utilization of the condenser for optimum efficiency under all operating conditions.

*How do ECR's Adaptiv™ Refrigerant Flow Controls differ from others?* The two controls are simple mechanical controls that respond directly to the temperature and velocity of refrigerant flow through the system. They modulate the amount of refrigerant in circulation to assure optimum efficiency at all times. By eliminating subcooling in the condenser, the system operates at lower refrigerant "head" pressures with increased mass flow, which reduces energy consumption and increases heat transfer system reliability and useful life. Is a two-speed compressor feasible with an EarthLinked® system? The velocity of the refrigerant that circulates for heat exchange in the earth loops is crucial because it must maintain a sufficient rate of circulation to continuously transport the compressor lubricating oil. A two-speed compressor would reduce the velocity to the extent that oil would not be returned to the compressor, which would be detrimental to the unit.
*Where is the compressor unit installed?* Because the EarthLinked® system does not require an outdoor coil and fan, the compressor unit can be located in a basement, utility room, garage or outdoors. A fully enclosed, well insulated cabinet assures quiet operation. Click to see photos and steps involved in an actual geothermal installation. *Can the system be used to heat water?* Yes. The EarthLinked® water heating options include desuperheating (providing "free" hot water in the cooling mode) and integrated "on-demand" for year-round domestic hot water. This unit can also provide hot water for radiant in-floor heating.
Is the EarthLinked® system ARI certified? Yes. The EarthLinked® system is rated according to ARI (the Air Conditioning and Refrigeration Institute) Standard 870 for Direct GeoExchange Heat Pumps. The average heating COP is 3.9, with a cooling mode EER of 17. The system is ETL safety listed and qualified under the EPA EnergyStar® program standards. *Are the EarthLinked® units that are sold in Europe different from those sold in the U.S.?* Yes. The compressors are suitable for 50 Hertz electrical supply and are Refrigerant R-407C compatible. A larger percentage of the systems sold in Europe are for heating-only because of a colder climate. Information provided by ECR Technologies, Inc. www.ecrtech.com