What Is Manometer Testing for HVAC Permit Compliance?

Manometer testing measures the pressure differences that prove an HVAC system meets energy code — duct leakage, airflow, and related verification — so the permit can close. In California it is performed by a certified rater, filed as a CF-3R, and required on most changeouts that touch the ducts or the equipment. A test that happened but was never registered does not close anything.

If a plan checker or a HERS rater has told you the job needs "manometer testing," the term can sound more exotic than it is. A manometer measures pressure difference. In HVAC energy-code work, that measurement is how a system proves it was installed correctly — and it is often the last thing standing between a finished install and a closed permit.

What a manometer actually measures

A manometer reads the difference in pressure between two points. On an HVAC job, that difference is the evidence:

• Duct leakage. The duct system is pressurized to a known level and the manometer measures how much pressure the system loses. Leaky ducts bleed conditioned air into attics and crawlspaces, so energy code sets a ceiling on how much leakage is acceptable. The manometer is what turns "the ducts seem fine" into a number a building department will accept.
• Airflow. Enough air has to actually move across the coil for the equipment to perform the way it was designed to. Pressure readings are used to verify airflow is within spec rather than assumed.
• Refrigerant charge. On split systems, verification confirms the charge is correct — an undercharged or overcharged system fails to deliver the efficiency the permit was issued against.

None of this is a formality. Each measurement is a pass/fail input to the compliance paperwork, and a fail means a correction and a retest.

When it is required

In California, this testing lives under Title 24. The 2025 California Energy Code took effect January 1, 2026 and expanded the set of HVAC work that triggers energy-code verification. HERS is now formally ECC, Energy Code Compliance; the field procedures are unchanged.

Replacements and alterations that touch the duct system or the equipment generally require verification before the permit can close. Two things follow:

1. The test is not optional — it is a code requirement tied to the permit.
2. The results have to be registered, not just performed. A test that happened but was never filed does not close anything.

The certificate of compliance — the CF-3R — has to be filed to a state-approved registry before the final inspection. If it is not in the registry, the inspector has nothing to sign off against, and the permit stays open.

Outside California, other states run their own energy-code verification regimes with different names and thresholds. The instrument is the same; the paperwork is not.

Who performs it

Manometer-based testing has to be performed by a certified rater, not by the installing tech's own judgment. Independence is the point of third-party verification.

Contractors generally have three options:

1. Hire an independent local rater per job. Works, but you are coordinating a second vendor's schedule against your install calendar, and in busy season that is where the delay shows up.
2. Bring rating in-house. Requires certification, calibrated equipment, and enough volume to justify both.
3. Use a provider that handles the testing and the compliance filing together. Fewer handoffs, and the test result and the CF-3R move as one workflow instead of two.

The third option matters more than it sounds, because the failure mode most contractors actually hit is not a failed test — it is a passed test whose paperwork never got registered, discovered weeks later when the final cannot be scheduled.

How this connects to HERS testing providers

Manometer testing is the instrument-level name for the duct-pressure half of HERS / ECC field verification. When contractors search for HERS testing providers, they are often searching for someone who will run this test, file the CF-3R, and not leave the permit hanging.

A provider that only shows up with a manometer is still a rater-only vendor. The useful configuration is the same one described in top HERS testing providers for HVAC and plumbing contractors: permit, test, and final inspection on one job record. The buyer's checklist is in what the best HERS testing service looks like.

How iPermit handles it

iPermit's own certified raters perform duct leakage testing, refrigerant charge verification, and airflow measurement. We are not brokering the work out to a third party and waiting on their schedule.

When testing is complete, we file the CF-3R through the CHEERS registry, so the compliance record lands where the building department expects to find it, before the final inspection rather than after.

Because we also pull the permit and schedule the final inspection, the test and the paperwork do not live in separate systems owned by separate vendors. One job record covers the permit, the testing, and the close-out.

iPermit has completed 500,000+ HERS tests and has been in the permit and compliance business for 50 years, since 1976. HERS and Title 24 testing is California-specific; permit services run nationwide, with local experts who know the building department. The service-page version of this instrument is manometer testing for HERS duct pressure compliance.

What causes a duct leakage test to fail?

Most failures trace to connections rather than the duct material — joints, boots, plenum connections, and register takeoffs. On retrofit work, the existing duct system is frequently the source rather than anything the crew installed that day.

Should ducts be sealed before the rater arrives?

Sealed, yes. Closed up and finished, no. If the system is buttoned up before the test, a failed measure means undoing finished work. Leave access until a passing result is recorded.

Does duct pressure testing apply outside California?

Title 24 field verification is California-specific. Other states run their own energy code regimes and most do not require the same duct testing on a residential changeout. Permit pulling and final inspections still run nationwide.

See HERS testing and how HERS testing helps HVAC contractors pass inspections. Talk to iPermit, or register at iPermitPro.com/signup.