'DX' Direct Exchange & Water Based Systems
The US Department of Energy (DOE) reports: "Geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies available. This technology has been keeping consumers comfortable for more than 50 years."
There are three basic Geothermal Technologies - Direct Exchange (DX), Closed Water Loops & Open Water Loops.
Direct Exchange 'DX' - uses refrigerant circulated in copper tubing as the heat transfer medium.
Closed & Open Water Loops - use water circulated in buried plastic pipes to transfer heat from the ground.
All use the same physics principle, using the earth as a 'heat source" and 'heat removal".
Along with two geothermal technologies comes more than one methodology to transfer geothermal energy from the ground into a structure. You can transfer the earths heat by circulating refrigerant in copper pipes ('DX' Direct Exchange) or circulating water through plastic pipes (water loops).
Both geothermal technologies are many times more efficient than conventional oil or gas systems. Consumers save up to 75% on annual heating and cooling bills. i.e. a 4000 sq. ft. home in Westchester, NY is comfortably heated and cooled for about $135. per month - all in! (request the case study).
The Geo Groups vast knowledge of building performance allows us to determine the best geothermal system for your application, structure and location. For most residential applications, 'DX' is the technology of choice. Both are incredibly efficient although based on physics, the 'DX' method is 30% more efficient. There are many applications where water loop systems better serve the project - such as larger commercial and industrial structures. In this case we would specify and install the system or combination of systems, most suited to the application.
Most HVAC and drilling contractors install one or the other. The rationale has more to do with their comfort level with installation rather than the appropriate technology and equipment for a specific application.
The Geo Group specializes in all technologies with firsthand experience in 'DX' Direct Exchange and Water Based Systems for residential and commercial properties.
The Inside Story on Geothermal
Efficiency - ’DX' has two heat transfers instead of three making it 20% - 30% more efficient. Natures preference. The reasons for higher efficiency aren't better engineering, but physics. Materials make a difference. Copper tubing, a superior heat conductor is the material used in DX systems. 'DX' requires fewer heat transfer steps resulting in a 20% 'DX' efficiency advantage.
Installation - less invasive requiring small shallow bore holes - only 3.5" requiring smaller equipment which can be maneuvered in tighter locations.
Refrigerant & Copper System - versus plastic tubing and water/glycol solution.
Low Maintenance - fewer repairs than water based systems, as reliable as your refrigerator. Fewer heat transfers, less moving parts.
Local Regulations & Restrictions - Water loop systems are approved in all 50 states. New Jersey allows only horizontal loop configurations for 'DX' installation, a more costly methodology. There is a strong movement by Engineers, Architects, Building Professionals and Environmentalist to change the municipalities outmoded local codes.
Manufacturers - there are ten (10) US based manufacturers making water based geothermal heat pumps. The 'DX' technology is supported by 2 manufacturers. 'DX' has a smaller (but growing) market share. Both technologies can present a challenge to locate an experienced designer or contractor. Making it that much more important to be sure you choose a geothermal company with proficiencies in both technologies.
System Reliability - both 'DX' and water loop systems have unsurpassed equipment reliability - especially compared to conventional heating and cooling systems. Frequency of repair is low for both technologies. The difference is Water loop systems require additional equipment and a plumbing circuit and 'DX' features only one moving part. Common wisdom is fewer moving parts, fewer repairs, improved longevity.
System Cost - 'DX' and Water loops systems are typically within 5% each other.
Bottom Line - worry less about the technology and more about the expertise and references offered by the contractor. Having proficiencies in both technologies will guarantee the best system design, quality and performance. Choosing geothermal by price alone is a recipe you may regret.
For A Free Estimate or to Learn More About Geothermal Technologies and Savings: Hudson Valley, NY, NJ, CT Call 844.500.4545
Delaware Valley, PA, DE
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