What this is

Duct leakage testing confirms that the heating and cooling duct system is properly sealed and not losing conditioned air into unconditioned spaces.

Why it’s required

Leaky ducts reduce system efficiency, increase energy use, and can prevent a project from meeting its modeled performance targets.

What is tested

The duct system is pressurized and measured to determine total air leakage relative to the system size.

What to plan for

All ducts, plenums, and connections should be fully installed and sealed before testing. Common issues include unsealed boots, leaky plenums, and reliance on building cavities as ducts.

Quality Insulation Installation (QII) verification confirms that insulation is installed correctly so it performs as intended under the Energy Code. Proper installation quality is as important as the insulation R-value itself.

QII applies when specified on the CF1R and focuses on installation sequencing and workmanship. The initial air sealing inspection must occur before insulation is installed. This inspection verifies that all required air sealing measures are completed while framing and penetrations are still accessible.

The insulation inspection must occur after insulation is installed but before drywall. Insulation must be in full contact with the conditioned surface, installed without gaps or compression, and supported to maintain continuous coverage. This inspection must also occur before the AHJ insulation or drywall inspection, as insulation must remain fully visible.

Once drywall is installed, QII verification cannot be performed and no QII certificate can be issued. If drywall is installed prior to QII inspections, the project will fail compliance and corrective action may require removal of finished materials.

To avoid delays and costly rework, QII inspections must be scheduled early and coordinated closely with framing, insulation, and drywall contractors.

This interactive CF1R provides a clear, field-accurate explanation of California Title 24 energy compliance requirements. Each HERS and ECC feature shown below reflects how the measure appears on an actual CF1R (Certificate of Compliance) and can be expanded to understand when it is required, what is verified in the field, and how pass/fail determinations are made. This page is intended for owner-builders, HVAC contractors, designers, energy consultants, and plan reviewers who need a practical, code-correct reference to CF1R requirements without simplifying or misrepresenting the California Energy Code.

Airflow verification confirms that the heating and cooling system is delivering sufficient airflow to meet Title 24 field verification requirements. The purpose of the test is to verify minimum system airflow, not to optimize system performance.

For compliance, the measured airflow must meet or exceed the applicable threshold based on project type. Alterations generally require a minimum of 300 CFM per ton, while new construction typically requires a minimum of 350 CFM per ton.

Higher airflow values, such as 400 CFM per ton, are commonly used as design targets and are also used to establish allowable duct leakage percentages during duct leakage testing. These values are not the pass/fail airflow verification thresholds.

Airflow is measured at the system or register level after installation. To avoid test failures, ductwork must be complete, filters installed, and the air handler configured correctly prior to testing.

Refrigerant charge verification confirms that the air-conditioning or heat pump system contains the correct amount of refrigerant to operate as designed. Improper charge can significantly reduce efficiency, capacity, and equipment life.

The verification method depends on the system type. Variable-capacity, inverter-driven, ductless, and many side-discharge heat pump systems are verified using a refrigerant weigh-in procedure. For these systems, refrigerant must be installed by weight based on manufacturer specifications, with required adjustments for line set length and indoor coil configuration.

For weigh-in systems, verification must occur during installation, at the time of evacuation and charging, and in the presence of the installer. Once the system is fully charged, sealed, and operating, this verification cannot be recreated. If weigh-in verification is missed, the project may fail compliance and require corrective action determined by the registry or provider.

Traditional fixed-speed split systems are typically verified using field measurements while the system is operating. This process includes measuring return air dry-bulb and wet-bulb temperatures, refrigerant pressures, refrigerant line temperatures, and outdoor ambient conditions to confirm that the charge falls within allowable tolerance.

To avoid compliance failures, the correct verification method must be identified in advance, and refrigerant verification must be scheduled at the appropriate installation stage based on the system type.

Indoor Air Quality (IAQ) verification confirms that required mechanical ventilation systems are installed and operating as designed to provide adequate fresh air and pollutant removal within the dwelling.

IAQ requirements are established by the CF1R and typically include whole-house ventilation and local exhaust, such as kitchen range hoods. Required airflow rates, equipment type, and control methods are defined during compliance modeling and must be met in the field.

Kitchen ventilation equipment must meet applicable airflow requirements and must be listed by AHAM or HVI when required by the compliance documentation. Many commonly installed range hoods do not meet these listing requirements, even when manufacturer airflow claims appear sufficient.

Verification may include confirming equipment listings, installation configuration, airflow performance, and sound ratings when applicable. To avoid compliance issues, ventilation equipment should be selected and reviewed early, installed per manufacturer instructions, and fully operational at the time of inspection.