Nonresidential Indoor Air Quality

Nonresidential Indoor Air Quality and Ventilation

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).

Measure Description

This measure proposes revising Title 24, Part 6 requirements using a combination of the requirements in Title 24, Part 4 (California Mechanical Code) and ASHRAE 62.1-2016: Ventilation for Acceptable Indoor Air Quality. The ventilation requirements in 2016 Title 24, Part 4 are based on or reference ASHRAE 62.1-2013. Therefore, aligning Title 24, Part 6 with select sections in Title 24, Part 4 will concurrently align with the corresponding section in ASHRAE 62.1-2016. All of the proposed changes would impact the mandatory requirements for ventilation in Section 120.1 of Title 24, Part 6. The specific recommendations include the following:

  1. Replace Section 120.1(b) with the ASHRAE 62.2-2016 requirements which apply to high-rise residential buildings.
  2. Require MERV 13 air filters for all ducted forced air system supply outdoor air or all occupancies.
  3. Revise Natural Ventilation criteria to align with ASHRAE 62.1-2016.
  4. Revise Mechanical Ventilation required ventilation calculation align with 130 percent of ASHRAE 62.1-2016 and include a simplified minimum ventilation rate calculation procedure.
  5. Update exhaust ventilation airflow requirements.
  6. Add recirculated air limitations.
  7. Delete Table 120.1 – A: Minimum Ventilation Rates and add in its place the System Ventilation Efficiency table.
  8. Add Table 120.1 – B: Minimum Ventilation Rates in Breathing Zone which uses the expanded list of occupancy categories at 130 percent of 62.1-2016.
  9. Add Table 120.1 – C: Zone Air Distribution Effectiveness.
  10. Add Table 120.1 – D: Minimum Exhaust Rates.