Effective October 1, 2005

The Institute of Heating and Air Conditioning Industries, Inc. (IHACI) and CHEERS © (California Home Energy Efficiency Rating Services) are working to provide you with as much information as possible on these rule changes.

When is duct testing required?
What is the maximum leakage rate allowed?
Who must perform the duct leakage test?
Must the duct leakage test be verified?
How do I find a CHEERS rater?

• When a building permit is applied for on or after October 1, 2005, for any of the following jobs:

The Air Handler, or
The outdoor condensing unit of a split system, or
A heating or cooling coil, or
The furnace heat exchanger
When adding or replacing 40 linear feet or more of ductwork in unconditioned space.

• When any of the following HVAC system components are replaced:

The air handler, or
The outdoor condensing unit of a split system, or
A heating or cooling coil, or
The furnace heat exchanger

When any of the above components are replaced, the duct system must be sealed regardless of whether the ducts are in conditioned or unconditioned space.

Exemptions:

If the ductwork is made of or insulated with asbestos, it is exempt from the duct sealing requirements.

The duct testing rules apply only in Climate Zones 2, 9, 10, 11, 12, 13, 14, 15 and 16.

The change-out rules apply to San Fernando and San Gabriel Valleys, the inland empire, and the high and low deserts are included.

Exempt areas are along the coast from San Luis Obispo to San Diego and most of Orange County.

These descriptions are approximate; refer to the local building department to confirm your climate zone.

If the duct system is entirely new, the maximum leakage rate is 6 percent of fan flow (24 cfm per nominal ton of capacity).

If 40 feet or more of new or replacement duct work is installed or if any of the HVAC components listed above are replaced, the maximum leakage rate may be any of the following:

• Fifteen percent of fan flow (60 cfm per nominal ton of capacity).
• The duct leakage is reduced 60 percent as measured prior to work beginning and after the work is completed plus a visual inspection verifies that all accessible leaks are sealed.
• If neither of the above two criteria can be met, all accessible leaks must be sealed by the contractor and verified by a HERS rater. Duct leakage to outside the house is 10 percent or less (this requires both a whole-house blower and duct tester to measure).