Geothermal Heat Pumps
Geothermal heat pumps transfer heat to and/or from the ground, enabling the pump to provide either or both central heating or cooling. This transfer occurs by using the earth or a body of water as a heat source during the winter and a heat sink during the summer. Geothermal heat pumps may also be referred to as ground-source heat pumps (GSHP), ground-coupled heat pumps, earth energy, and GeoExchange.
CDH Energy has monitored numerous geothermal heat pump systems and assessed performance in both residential and commercial buildings, by employing comprehensive field monitoring technologies and techniques. Our experience is geographically and technically diverse, having collected field data from dozens of systems in New York, Wisconsin, Georgia, and North Carolina. These analyses include the evaluation of electrical and thermal efficiency, energy use, comfort, and installation methods, along with assessments of the local market.
CDH has worked with many different geothermal system configurations that include, but are not limited to, open loop, closed loop vertical, horizontal, slinky, and direct expansion (DX) platforms.
CDH Energy has monitored and evaluated numerous residential geothermal heat pump systems, including:
- 12 systems for Duke Power
- 14 systems in Georgia for the Jackson Electric Membership Coop and the National Rural Electric Cooperative Assoc.
- 4 systems in New York for the Empire State Electric Energy Research Corporation
- 1 for the New England Power Service Company
- 8 sites for the Energy Center of Wisconsin
We monitor system electricity use, ground loop temperatures, and air-side conditions in order to accurately analyze data and provide answers to our clients.
From the collected data, we perform energy balances and quantify the economic, technical, and environmental performance of each system. We have also use such data to compare various configurations and technologies alongside conventional systems, and to identify promising heat pump technologies and installation techniques.
CDH has practical experience conducting feasibility studies, providing data verification, developing monitoring plans, collecting data, and performing analyses for commercial and institutional geothermal heat pump systems across the country. Our commercial, institutional, and municipal geothermal heat pump background includes:
- Data collection and analysis for multiple ARRA-funded geothermal demonstration sites nationwide for the Oak Ridge National Laboratory.
- Feasibility studies on GHP technologies for two schools for the Wisconsin Department of Administration Energy Bureau
- Monitoring of various commercial and municipal geothermal heat pump sites ranging from 20 to 300 tons for the Geothermal Heat Pump Consortium.
We developed engineering case studies that demonstrate GHP design options including thermally-enhanced grout, bore field piping size, standing column wells, and building pilings in place of a dedicated bore field. The systems we monitored include:
- Geneva Lake Front Hotel - Vertical Bore Field
- Haverhill Public Library - Standing Column Well
- Dubuque County Courthouse - Open Well
- Water Tower Square - Open Ground Water
We met with building owners and design teams throughout Wisconsin, introducing them to geothermal technology and guiding initial feasibility analysis for the Focus on Energy program. Support included reviewing preliminary designs, estimating costs, and locating contractors for testing, design and installation.
We have also provided regional market support for geothermal heat pumps. For example, CDH reviewed the commercial geoexchange market in New York State for NYSERDA’s Geothermal Heat Pump Consortium, and developed a guide to assist owners and design teams understand and assess geoexchange for their projects.
- Case Study of the ARRA-Funded GSHP Demonstration at the University at Albany (4.1 MB)
- Field Testing Results for Ductless Heat Pumps in Cold Climates (3.0 MB)
- Case Study of the ARRA-Funded GSHP Demonstration at the Natural Sources Building, Montana Tech (11.4 MB)
- Overview of Geothermal Heat Pumps (1.8 MB)
- Implications of GHP Fan Control Strategies on Humidity Control (464 KB)
- Open Loop GSHP Application at Dubuque County Courthouse (430 KB)
- Experiences from Geothermal Heat Pump Systems with Variable Flow Pumping (347 KB)
- North American Monitoring of a Hotel with Room Size GSHPS (343 KB)
- Innovative Commercial "Ground Source" Heat Pump System Sources and Sinks (1.3 MB)
- Market Assessment of New Heat Pump Technologies (800 KB)