Measure Overview
This proposal would add the following requirements for new and replacement air dryers:
- Trim air compressors would have a dedicated air dryer separate from those for baseload compressors.
- Where necessary plant dewpoints are greater than 35°F, refrigerated dryers would be specified. A non-cycling air dryer may be specified for baseload air compressors while cycling refrigerated dryers would be specified for trim air compressors.
- All desiccant dryers would have dew point measurement display and controls that reduce regeneration consumption based on load. Air compressor systems with a target dewpoint greater than or equal to -100°F would use a heated desiccant dryer (inclusive of heated blower purge dryers).
- Air dryer field verification testing that confirms:
- Dryer schedules overlap with plant and air compressor schedules.
- Desiccant dryer dewpoint setpoints and demand-based regeneration are commissioned properly.
Provide Feedback
This measure page will be updated as the 2028 code cycle progresses. For questions or suggestions, submit feedback to [email protected]. Please include the measure name in the subject line.
View the Energy Commission's proceedings and available proposed code language by visiting their CEC 2028 Proceedings Website page.
Scope 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 | Mandatory | no updates | Add new verification requirements |
Justification for Proposed Change
Air compressor systems were first covered by Title 24 Part 6 in 2013 thanks to efforts by the California Statewide Codes and Standards Enhancement (CASE) Program team. Mandatory covered process measures were added that stipulated sizing and control requirements for baseload and trim air compressors. Through another CASE Program effort, additional compressed air system requirements were added as part of the 2022 code cycle with a focus on optimization and sustained efficiency of the distribution and load-side components. This CASE effort added mandatory pipe sizing, monitoring, and leak testing measures to Title 24 Part 6.
The proposed 2025 air dryer code measure additions originated during the development of compressed air system measures for the 2022 energy code cycle. Air dryer measures were not pursued at that time, although not due to any technical or cost-effectiveness barriers. Rather, dryers were excluded simply because the selected measures focused on the distribution system and load-side of compressed air, of which dryers were not considered. Air dryer requirements were identified as a possible measure during discussion and measure selection amongst the Statewide CASE team but were not prioritized at the time and were instead reserved for future efforts.
The team is not aware of any ongoing appliance or energy efficiency standards that cover compressed air dryers or their selection. Air dryer types and selection are discussed in industry documents such as the Compressed Air and Gas Handbook from the Compressed Air and Gas Institute, but no standards or code language yet exists.
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.