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Ground-Source Heat Pumps
GSHP Systems

A ground-source heat pump (sometimes called a "geothermal heat pump") provides space conditioning by moving heat energy. A ground-source heat pump (GSHP) system can provide heating, cooling and humidity control. A GSHP system may provide water heating, either to supplement or replace conventional water heaters. 
 
Every GSHP system has three major subsystems or parts: a geothermal heat pump to move heat between the building and the fluid in the earth connection, an earth connection for transferring heat between its fluid and the earth, and a distribution subsystem for delivering heating or cooling to the building. 
 
In heating mode, heat is extracted from the fluid in the earth connection by the geothermal heat pump and distributed to the home or building -- typically through a system of air ducts. Cooler air from the building is returned to the geothermal heat pump, where it cools the fluid flowing to the earth connection. The fluid is then re-warmed as it flows through the earth connection. 
 
In cooling mode, the process is reversed. The relatively cool fluid from the earth connection absorbs heat from the building and transfers it to the ground. 

Ground Source Heat Pump Compressor Upgrade

    Must comply with the following requirements

  • All units must be installed on systems that comply with OAR 330-070-0025, 330-070-0040 and 330-070-0070. See also OAR 330-070-0027.
  • All units must be installed on systems that use an operational closed-loop ground coupled heat exchanger. Open-loop systems do not qualify.
  • The compressor upgrade unit must be sized within 15 percent of the unit it is replacing, based on rated cooling capacity in Btus. The department may grant an exception to this limit for an upgrade that is accompanied by a written justification including measured data and appropriate engineering calculations. 

Tax Credit
 
High performance ground source heat pumps are eligible for a Residential Energy Tax Credit when installed by a tax credit certified geothermal technician. The equipment specifications are:
  • must be closed loop systems;
  • must have a performance rating of 3.3 COP for closed loop or 3.5 COP for direct exchange (DX) systems
 
Water well reinjection systems or other "pump and dump" systems are not eligible for the Residential Energy Tax Credit.
 
Geothermal Heat Pump
Yield Table

System Tons  BTU per Hour Output  Estimated Savings  Tax Credit Amount 
3 ton and under Less than 40,000 1,000 kWh $600
4 ton 40,000 - 49,999 1,165 kWh $700
5 ton 50,000 - 64,999 1,335 kWh $800
6 ton and over 65,000 and over 1,500 kWh $900
 
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