OAR 330-070-0070
Geothermal Systems
(1)
Geothermal systems must comply with OAR 330-070-0025 (Application for System Certification) and 330-070-0040 (Other Rules and Regulations). Installations must be verified by a tax-credit technician.(2)
System parts must have adequate:(a)
Structural strength;(b)
Resistance to weather and fire;(c)
Ease of upkeep; and(d)
Durability.(3)
Systems must fully protect drinking water as specified in the Oregon Plumbing Specialty Code and be designed for the least impact on ground water.(4)
Direct use geothermal systems must include a summary report from Oregon Institute of Technology or other source approved by the Director which describes the system and indicates that it will deliver sufficient heat and the design meets current good practice guidelines. These systems will be reviewed on a case-by-case basis.(5)
The system Coefficient of Performance (COP) must be at least 3.3 for all systems including energy used by pumps, except 3.5 for direct expansion (DX) systems including energy used by pumps. COP will be determined by the following methods:(a)
For water source heat pumps, the COP must be determined in accordance with ANSI/AHRI/ASHRAE/ISO Standard 13256-1, at an entering water temperature of 50 degrees F.(b)
For solar assisted heat pumps, the COP must be the measured ratio of the heating season energy output divided by the heating season energy input. Both energy values must be expressed in the same units.(6)
All other types of geothermal systems must be reviewed on their COP.(7)
Geothermal upgrade systems must comply with the following requirements:(a)
All units must be installed on systems that comply with these rules.(b)
All units must be installed on systems that use an operational closed-loop ground coupled heat exchanger.(c)
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.(d)
All units must be manufactured by a company appearing in the Air-Conditioning, Heating and Refrigeration Institute (AHRI) Unitary Directory.(e)
Post-upgrade system COP must be at least 3.3 for closed loop systems and 3.5 for direct expansion (DX) systems, including energy used by pumps. COP must be determined by the following methods:(A)
For water source heat pumps, the COP must be determined in accordance with ANSI/AHRI/ASHRAE/ISO Standard 13256-1, at an entering water temperature of 50 degrees F.(B)
For water source or ground loop heat pumps using ambient surface water as an energy source and for solar assisted heat pumps, the COP must be the measured ratio of the heating season energy output divided by the heating season energy input. Both energy values must be expressed in the same units.
Source:
Rule 330-070-0070 — Geothermal Systems, https://secure.sos.state.or.us/oard/view.action?ruleNumber=330-070-0070.