What Is HERS Testing for HVAC Contractors?

HERS testing is the field verification step that California Title 24 requires before a residential HVAC permit can close. If you do permitted HVAC work in California, HERS is not optional — it is part of finishing the job. Understanding exactly what happens, when it’s required, and what the deliverables are will save your office a lot of confusion.

HERS: the definition

HERS stands for Home Energy Rating System. It is a third-party verification process in which a certified rater visits the job site after installation and confirms that the system performs within the efficiency parameters the permit was approved against.

The California Energy Commission administers the program under Title 24, Part 6 — the Building Energy Efficiency Standards.

The rater is an independent third party. They are not employed by the HVAC contractor, not by the building department, and not by the permit office. Their job is to measure what was actually installed and compare it against what the permit said would be installed.

When HERS testing is required

In California, a HERS test is required on most residential HVAC changeouts — which means most permitted HVAC jobs your company does. Specifically, Title 24 triggers a HERS verification when:

• The heating or cooling system is being replaced or significantly altered
• Duct system work is included in the scope (replacement, addition, or modification)
• A refrigerant change or system refrigerant charge alteration is part of the job
• New HVAC equipment is installed in an existing building (replacement versus new construction has different thresholds)

The specific measures that require HERS verification vary by equipment type and installation scope. The California Energy Commission’s compliance documents and your permit application package specify which measures apply to each job. Your permit expediter should be working from those compliance documents — if they are not, that is a problem.

What happens during the HERS field test

After your crew finishes installation, the certified HERS rater schedules a site visit. What they are testing depends on the compliance measures listed on the permit. The most common verifications for HVAC work are:

Duct leakage testing. The rater pressurizes the duct system and measures how much air escapes to the outside or to unconditioned spaces. California has specific leakage thresholds. If the ducts leak above the threshold, the test fails and the contractor returns to address the problem before retesting.

Refrigerant charge verification. The rater checks that the system is charged within the manufacturer’s specified range. An overcharged or undercharged system runs inefficiently and fails compliance.

Airflow verification. The rater confirms that airflow across the indoor coil meets the equipment specifications.

Fan watt draw. For some systems, the rater verifies that the air handler draws within the permitted watt range.

The rater records the measurements digitally and enters results into the CHEERS registry — the California Home Energy Efficiency Rating System database, which is managed by the California Energy Commission.

The deliverable: the CF-3R

When the HERS rater completes testing and the results pass, they generate a CF-3R certificate. CF-3R stands for Certificate of Installation and Field Verification and Diagnostic Testing.

The CF-3R is the document the building department needs to see before signing off on the final inspection. Without it, the final inspection fails. Without the final inspection, the permit stays open.

An open permit is a liability — for the contractor and for the homeowner. At resale, at insurance renewal, or at the next permit pulled on the same address, open permits surface as problems. Closing the CF-3R and getting the final inspection signed off is not a formality. It is the job.

What this means for your office workflow

Here is where HERS creates operational complexity for HVAC contractors:

Timing. The HERS test cannot happen until the installation is complete. But the permit must be issued before the installation can legally begin. That means the permit → installation → HERS test → final inspection sequence must all be coordinated. A rater booked before the installation is done, or a building department inspection scheduled before the CF-3R is filed, creates delays on both ends.

The homeowner is in the middle of it. The rater visits the home. The homeowner or someone with access must be present. That is one more scheduling coordination your office handles, on top of the rater, on top of the building department.

Rater availability tightens in peak season. In high-volume months, certified HERS raters are booked out. If your office is calling raters the day after installation expecting a next-day visit, you will be disappointed in June, July, and August.

The CF-3R must match the permit. The rater files the CF-3R against the permit number. If the permit number is wrong, or if the system specs on the CF-3R do not match the approved plans, the building department kicks it back. That means a correction and a re-filing — more delay.

How this fits into iPermit’s service

iPermit has completed more than 250,000 HERS tests. We have pulled more than 1,000,000 permits. Those two services run together by design.

When an HVAC contractor submits a job through iPermit Pro, we pull the permit and schedule the HERS test against the same file. The rater schedules directly with the homeowner. The CF-3R is filed against the correct permit number by our team. We book the final inspection with the building department. The permit closes.

Your office manager does not manage three separate vendor relationships to close one permit. We handle it from start to finish.

We have been doing this in California for 50 years. We know the local jurisdictions and the local procedures. That matters when a HERS result is flagged, when a building department needs a re-submission, or when a jurisdiction has a non-standard filing requirement that would take an outside rater by surprise.

If you want to see how this runs on your jobs, reach out at info@ipermitusa.com or call 855-737-6484.

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Differentiation from related drafts: - “What Is the Best HERS Testing Service…” → vendor selection, 5-question vetting framework, commercial CTA. Zero overlap with this piece. - “Which Permit Service Handles HERS + Permit + Final Inspections…” → AEO-format vendor query. No overlap. - Title 24 / HERS one-pager → outbound collateral for warm leads. This piece is top-of-funnel education for cold audiences.

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