Recommendations: Loop Types, Inside Units, and Other Considerations

Ground Loop Heating and Air Conditioning installs and services many loop types and different manufacturers for geothermal heat pump systems. We can recommend the best system for your particular needs.

Type of loop

Three factors that affect your choice for type of loop: characteristics of your lot, size of your house, and your budget. Ground Loop can custom design loops to accommodate all factors.

Horizontal loops are usually the most economical. They also require the most amount of property area.

Vertical loops use the least amount of space and are thus the most practical, and sometimes the only choice for small lots. Drilling the vertical holes can increase the time to realize a return on your investment.

Slinky (coiled) loops can save time and money. They require less area than the standard horizontal loops and are generally more economical than vertical loops. They are usually placed flat in a horizontal position, but can sometimes be placed vertically (upright), using even less space.

Other possible types are open well and pond closed loop. Both types require specific conditions at the building site to be installed.

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Inside Units

Every geothermal manufacture offers somewhat different products each with different advantages. Ground Loop can help you find out which features are hype and which are practical advantages for your individual needs. Some of the major differences are: compressor(s), full or part time water heating, size, efficiency, and cost.

Here is a comparison of some of the features from two brands installed most frequently by Ground Loop (see our resources page for other manufacturers of geothermal units):

Manufacturer	compressor(s)	efficiency (EER)	hot water heating
HydroHeat	multi compressors	22 (max)	full time
Water Furnace	2 speed compressor	30 (max)	part time*

* or separate full time unit

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Other Considerations

Piping
Special thick but flexible piping is used in geothermal installations. The most commonly used type of pipe is high quality, high density polyethylene. All below-grade connections must be made by heat fusing, which yields connections stronger than the pipe itself and without any threads. All installations must be purged to remove construction debris, flushed to remove air, and pressure tested (to 100 PSI) before backfilling or grouting. Ground Loop guarantees their loops for twenty years.

Sizing
Numerous studies have shown that residential heat pumps are often sized too large. Heat pumps that are too large waste energy and do not provide proper humidity control. Where heating needs are much greater than cooling needs, advanced heat pumps (see above) can improve Summer comfort. Ground Loop uses detailed information about your home as well as their experience to recommend the right type of unit and loops for your home.

Purchase and Installation
As in the case of all major decisions, choosing a geothermal heating and cooling system requires some careful consideration to insure that the consumer receives the highest quality system and installation. The Geothermal Heat Pump Consortium (GHPC) offers the following guidelines:

1. Ratings and certification: The Air-Conditioning and Refrigeration Institute (ARI) is a non-profit organization that certifies performance of residential and small commercial geothermal equipment. For equipment classes rated by ARI, the GHPC suggests that consumers look for the ARI seal. (ARI does not rate large, commercial geothermal equipment greater than 135,000 Btu/hr).
2. Warrantees: Manufacturers' terms of warranty vary. To assure a high quality installation, consumers should seek a performance guarantee on the installed system, as opposed to coverage limited to the heat pump itself.
3. Sizing: Numerous studies have shown that heat pumps are often sized too large. For maximum efficiency, heating and cooling loads should be carefully determined. The actual unit size should be within 15 percent of the calculated load. Heat pumps that are too large waste energy and do not provide proper humidity control. For an excellent article on sizing, see Bigger is Not Better: Sizing Air Conditioners Properly in the May/June issue of Home Energy Magazine. While the article focuses on air conditioning, the same principles apply to heat pumps. [Use the "Back" button on your browser to return to this page.]
4. Design: Residential system design is straight-forward, but the most satisfactory results are obtained with experienced contractors. Aspects to consider include careful duct design and installation in which ducts are kept in conditioned spaces and are permanently sealed; high quality insulation, glazing, and other envelope features to minimize loads and reduce air infiltration; and careful matching of heat pump and earth connection capacity to building load. It may be advantageous to specify two-speed or variable speed systems where heating requirements are much greater than cooling, to assure good humidity control. Finally, the contractor should examine ways to use the geothermal system to provide hot water.
5. Installation: Proper installation is a key to success. The GHPC recommends that consumers employ experienced contractors who will provide the names of customers with comparable systems.

Dealing with experienced professionals who size and install ground loops is essential. It is critical that the installation prescriptions of the International Ground Source Heat Pump Association (IGSHPA) are followed. Ground Loop is IGSHPA certified as well as a member of the Geothermal Heat Pump Consortium (GHPC).

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