Measure Overview
This measure would prescriptively require circulator pumps serving central water heating systems in nonresidential buildings to have advanced digital pump controls. Applicable controls would include internal or external controls that reduce energy use at the pump and/or water heater. The proposed control requirements would vary based on building size, application, water heating plant types, and distribution system designs. Proposed continuous pump control methods include but are not limited to pressure based variable speed control with thermal balancing valve(s), constant return temperature control, demand flow-based control, aquastat, and digital timeclock. The proposed measure would be applicable to new construction, alterations and additions.
This measure would include a reference appendix to add startup and field verification requirements for contractors based on the application and pump control strategy. Field verification would be via self-attestation on the design (NRCC) and installation (NRCI) forms.
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The Statewide Utility Codes and Standards Team is conducting a survey to inform nonresidential code change proposals for the 2028 California Building Efficiency Standards (Title 24, Part 6).
In appreciation, we will send you a $20 Tango gift card or donate this amount to your local United Way upon completion of the survey.
Take the SurveyScope of Proposed Code Change
| Building Type(s) | Construction Type(s) | Type of Change | Updates to Compliance Software | Third Party Verification |
| Nonresidential | New construction, additions, alterations | Prescriptive | Update existing feature, add new feature | No changes to third party verification |
Justification for Proposed Change
Currently, there is a mandatory requirement that circulating pumps are capable of automatically turning off. There are no prescriptive requirements for advanced digital pump controls in Title 24, Part 6 for nonresidential buildings with central water heating systems. Although the experience of the Statewide CASE Team suggests that aquastat and analog timer controls are commonly installed in nonresidential buildings, these control types have longevity challenges.
Several studies have evaluated the benefits of ECM pumps and controls including the High-Performance Circulator Pump Demonstration Study by National Renewable Energy Laboratory (NREL) (Dean, Honnekeri, & Barker, 2018) and Extended Motor Products Savings Validation Research on Clean Water Pumps and Circulators by Northwest Energy Efficiency Alliance (NEEA) (Group, 2019). The NREL study suggests that the domestic hot water pumps electricity savings range from 90 percent to 96 percent with a simple payback period of 3 to 4 years. Based on the NEEA study results; ECM pumps provide approximately 50 percent savings while added controls can provide up to 84 percent electricity savings at the circulator pump. These studies do not evaluate the potential energy savings at the water heater. Based on these two studies, this measure is highly cost-effective.
In addition to the above studies, TRC and 2050 Partners are working on a field demonstration study for circulator pump controls. The Statewide CASE Team will leverage data from this study to inform the energy savings for the proposed measure.
Relevant Documents
Round One Utility-Sponsored Stakeholder Meeting Materials
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Give Us Your Feedback
The Statewide CASE Team values input from all stakeholders engaged in the Title 24, Part 6 code change process. We encourage the open exchange of code change comments and concerns.