Does an HVAC Replacement Need Title 24?

Why a like-for-like changeout is still regulated

This surprises people, because nothing about the house is changing. But the code names these replacements specifically: swapping the air handler, the outdoor condensing unit of a split-system air conditioner or heat pump, or a cooling or heating coil is an alteration that brings the duct system into scope along with the equipment.

The duct thresholds

When the equipment is replaced, the duct system connected to it has to be sealed and tested: total leakage of 10 per cent of the air handler's airflow or less, or leakage to outside of 7 per cent or less. If neither can be reached, every accessible leak is sealed and confirmed by an ECC-Rater with a visual inspection and a smoke test. It is a whole-system test, not a test of the new parts: the new equipment is what triggers it, but the old ducting is what usually fails it.

New ductwork has its own trigger. Installing more than 25 feet of new or replacement duct brings the ducts under the same sealing rule and the insulation levels for ducts outside the conditioned space, and an entirely new duct system has to reach 5 per cent.

There are exemptions from the equipment-change test: duct systems with less than 40 linear feet of duct, systems already sealed and tested by an ECC-Rater, and ducts built, insulated or sealed with asbestos. Ducts, air handlers or coils in a garage have a separate rule that applies whatever the length.

What that means for the paperwork

Where an altered space-conditioning system is not exempt from field verification, the alteration form has to be completed and registered with an ECC provider's data registry, and a rater has to verify the work. That is a scheduling dependency, not just a document: the test happens on site, with the system installed.

The practical read

A straight condenser swap that touches almost no ducting is a light-touch job. The same swap on a house being reducted is a different project, and the duct test is the part most likely to fail first time in an older house. Establishing roughly how much duct is being replaced, before the work starts, is what decides which of those two you are in.

Switching to a heat pump, or adding central air where there was none, carries further requirements: see Title 24 heat pump requirements and does adding central air need Title 24?

Common Title 24 Questions

1. When is Title 24 required for a home?
2. Does a remodel need Title 24?
3. Does a room addition need Title 24?
4. What plans are needed for a residential Title 24 report?
5. How much does a residential Title 24 report cost?
6. How long does a residential Title 24 report take?

Explore Building Permit Questions

1. JA12 Battery Storage Requirements
2. Kitchen Expansion Title 24 Requirements
3. Does an Electrical Panel Upgrade Need Title 24?
4. Repair or Alteration? When Fixing Something Does Not Trigger Title 24
5. Replacing Light Fixtures Under Title 24

View all Building Permit Questions guides → · Permits and Compliance · Title 24 guide