HVAC Permits and HERS Testing in California: What a Legit Replacement Includes

Why permits matter for HVAC

A permit puts a city inspector and, usually, an independent HERS rater between you and a bad install. In the City of San Diego, for example, the code says HVAC equipment shall not be installed, altered, replaced or repaired unless a mechanical permit has been obtained, and many single-family replacements can get a No-Plan permit online.

Unpermitted work can surface when you sell, can complicate insurance claims, and gives you no third-party check on duct leakage or refrigerant charge.

What triggers HERS testing

California's Energy Code treats a system as "altered" when a refrigerant-containing component (cooling coil, condenser coil, compressor or outdoor unit) or the air handler is replaced. An altered system's ducts generally have to be leak-tested by a HERS rater, an inspector certified through a California Energy Commission-approved provider and independent of the installer.

Simple repairs, like replacing a blower wheel without replacing the heat exchanger or air handler, don't count as an alteration and don't trigger these rules.

• Altered system: duct leakage of 15% or less of air handler airflow.
• Entirely new system with more than 75% new ducts: 5% or less, plus airflow and fan watt checks.
• Any altered duct in a garage: 6% or less, or seal and verify visually with a smoke test if it can't be measured.
• Duct extensions over 40 feet: 15% or less. Extensions of 40 feet or less outside a garage: no test, just insulation.

The paperwork trail

The installing contractor registers a compliance form (CF1R-ALT-02-E for ducted or AC projects) with a HERS provider before applying for the permit, then completes a certificate of installation. The HERS rater registers verification forms covering duct leakage, fan efficacy, airflow and refrigerant charge as applicable. Those have to be on file before final inspection.

Climate zone details

Some requirements change by building climate zone. Inland Climate Zone 10 cities such as Escondido publish their own alteration checklists; Escondido's calls for R-8 duct insulation on altered and new duct systems and MERV 13 filters on fully replaced systems with more than 10 feet of ducting.

How to spot a quote that skips it

Read the line items before you compare prices.

• No permit fee, or "permit optional" language.
• No mention of HERS testing on an AC or heat pump replacement.
• A cash discount for skipping the permit.
• No license number on the quote.