Cooling Tower Minimum Efficiency

Nonresidential HVAC

Codes and Standards Enhancement (CASE) Report

The Statewide CASE Team 2019 Title 24, Part 6 Final CASE Report is available below. The Final CASE Report incorporates feedback received during utility-sponsored stakeholder meetings, Energy Commission Pre-Rulemaking workshops, and personal communication with stakeholders. We encourage stakeholders to email feedback on the Final CASE Report to You can also participate in the 2019 Title 24, Part 6 Standards updated by attending the Energy Commission workshops and submitting written comments to the rulemaking docket. Refer to the Pre-Rulemaking and Rulemaking Workshop Notices for instructions on how to submit comments to the Energy Commission’s docket (available here).

Final CASE Report: Nonresidential Cooling Tower Efficiency

Draft CASE Report: Nonresidential Cooling Tower Efficiency

Measure Description

The CASE Report proposes a prescriptive requirement for higher efficiency axial fan open-circuit cooling towers for newly constructed projects, new systems that serve additions, and non-building mounted replacements/alterations. The current 2016 Title 24, Part 6 Standards’ mandatory minimum efficiency for axial fan open-circuit cooling towers is 42.1 gallons per minute of condenser water flow per fan horsepower (gpm/hp). The 2016 Alternate Calculation Method Reference Manual assumes an efficiency of 60 gpm/hp for a standard design cooling tower. The intent of this proposal is to add a prescriptive efficiency requirement of 80 gpm/hp in addition to the mandatory requirement and to increase the standard design listed in the Alternative Calculation Method (ACM) Reference Manual to 80 gpm/hp. The measure proposes this prescriptive requirement only for condenser water systems that are rated for 900 gpm (300 tons) or greater.