Duct Leakage Testing

Your duct system is the delivery network for every dollar you spend heating and cooling your home. When ducts leak into attics, crawlspaces, or wall cavities, that conditioned air never reaches your living space — and the average leaky California duct system loses 20–30% of its airflow this way. The result is higher utility bills, rooms that never quite reach temperature, and an HVAC system that runs longer and wears out faster than it should.

Leaky return ducts create a second problem: they pull air in from attics and crawlspaces, dragging dust, insulation fibers, and moisture into the air you breathe. That is why California made duct leakage testing a mandatory part of Title 24 compliance rather than an optional upgrade.

Under Title 24, the contractor who installs or seals your ductwork cannot verify their own work. The leakage test must be performed by an independent, certified ECC rater (formerly HERS rater) trained and certified under the California Energy Commission's Energy Code Compliance program. The rater pressurizes the duct system with calibrated equipment, measures exactly how much air escapes, and registers the official CF3R compliance forms your building department requires.

T3 Energy Inc.'s raters are fully ECC certified and have performed duct testing on thousands of Sacramento-area homes. Because we test every day, we can also tell your contractor exactly where a failing system is likely leaking — so repairs are fast and the re-test passes.

Title 24 requires a duct leakage test on most new HVAC installations, complete system replacements, and alterations that add or replace more than 40 feet of ductwork. If your project pulled a mechanical permit — and in California, furnace, AC, and heat pump change-outs always should — a duct test is almost certainly required before the building department will complete your final inspection.

Even outside a permit, duct testing is worth doing any time you suspect comfort problems, dusty air, or high bills. A one-hour test tells you definitively whether your ducts are the culprit.

Our rater seals every supply register and return grille, connects a calibrated duct pressurization fan, and brings the duct system to a standard test pressure of 25 Pascals. A digital manometer measures the airflow required to hold that pressure — that number is your total duct leakage, compared directly against the Title 24 allowance for your project type. You get the pass/fail result on the spot, and passing systems have their CF3R forms registered the same day in most cases.