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Residential Indoor Air Quality and Ventilation

Indoor Air Quality and Ventilation

Codes and Standards Enhancement (CASE) Report

The Statewide CASE Team is requesting feedback on the 2019 Title 24, Part 6 Draft CASE Reports. The CASE Report presents pertinent information that supports the code change proposal. Please email feedback to You may also submit written comments to the Energy Commission. See the agenda for Energy Commission pre-rulemaking workshop (available here) for instructions on how to submit comments to the Energy Commission’s docket.

Draft CASE Report: Residential Indoor Air Quality

Measure Description

This measure adopts ASHRAE Standard 62.2-2016 (with modifications), which changes requirements for mechanical ventilation in all building types, and reclassifies high rise residential buildings as falling under ASHRAE Standard 62.2 instead of 62.1. Specific related sub-measures vary by building type as follows:

All residential building types:

  • Calculates the mechanical ventilation rate based on an assumed infiltration credit equivalent to 2 ACH50 which varies by climate zone;
  • Increases filter efficiency requirement from MERV 6 to MERV 11 (or equivalent);
  • Requires verification of kitchen hood venting to exterior, airflow rating, and sound rating. Ventilation rates will increase for single family and low rise residential buildings.

Multifamily residential including high-rise residential:

  • Requires makeup or relief air for ventilation;
  • For buildings using central ventilation shafts, requires verification of shaft leakage rates, and of required ventilation delivered to each unit using automatic dampers or other means. Under 62.2-2016 ventilation rates will increase for low rise and will decrease for high rise (ventilation using windows no longer permitted). Also, checklists currently used to verify building sealing may be modified to enhance compartmentalization (reduce unit-to-unit air exchanges).

This measure also resolves conflicting language in Title 24 Parts 2, 4 and 6 and defines the specific types of buildings currently covered by Part 4 that will be covered by Part 6.

Request for Feedback

The Statewide Utility Team encourages participation in the CASE Report development process through the submission of data—both primary sources and references to existing data. We are requesting data on areas such as energy savings, costs, market impacts, industry practices, barriers to code compliance, etc. from stakeholders. The data will inform the energy savings estimates, cost-effectiveness analysis, compliance and enforcement, and market impacts that will be presented in CASE Reports.

Do you have feedback or data to share? Send us an email at


Reseouces Developed By Statewide CASE Team

  1. September 2016 Utility-Sponsored Stakeholder Meeting Presentation
  2. September 2016 Utility-Sponsored Stakeholder Meeting Notes 
  3. March 2017 Utility-Sponsored Stakeholder Meeting Presentation
  4. Draft Code Language, posted March 2017

Other Reseouces 

  1. Purchase ASHRAE Standard 62.2 here.
  2. Brett Singer (LBNL) completed a study looked at 8 variations of ventilation systems. The report is available here.
  3. Energy Commission’s Authority & Responsibility Regarding Indoor Air Quality
  4. An example of a new Title 20 air filter labeling is shown below:

California Statewide Utility Codes and Standards Program

This program is funded by California utility customers and administered by Pacific Gas and Electric Company, Southern California Edison, San Diego Gas and Electric Company, Southern California Gas Company, Sacramento Municipal District, and Los Angeles Department of Water and Power in preparation for the California Energy Commission’s Codes and Standards Buildings Advocacy.