AIRCERT
← AirCert home
EPA compliance · free tool
R-134a leak rate calculator
Built to 40 CFR 84.102 and 84.106 · the AIM Act rule in force since January 1, 2026
Put in the full charge and the R-134a you added. This runs whichever of the EPA’s two methods you use, checks it against the threshold for the appliance type, and shows the arithmetic so you can put it straight in the record.
Calculation method
Capped at 365. Calculating for the first time since January 1, 2026? Use 365.
Calculated leak rate
—
Fill in the full charge and the pounds added.
Nothing you type here is sent anywhere or stored. The sum happens in your browser.
Is R-134a covered?
R-134a is a regulated substance in its own right.
R-134a is itself one of the HFCs regulated under the AIM Act, so any appliance with a full charge of 15 pounds or more is covered by 40 CFR 84.106. The residential and light commercial air conditioning exemption rarely helps, because R-134a is not typically used there.
R-134a is the refrigerant most likely to make you stop and think about which band you are in, because it turns up in three different jobs: centrifugal chillers cooling buildings, medium-temperature commercial refrigeration, and refrigerated transport. Those are three different thresholds.
It depends entirely on what the appliance does
A centrifugal chiller cooling a building is comfort cooling at 10%. A medium-temp system keeping product cold is commercial refrigeration at 20%. Process cooling in a plant is industrial process refrigeration at 30%. Refrigerated transport is named explicitly in the 10% band. Pick the appliance type in the calculator before you read the verdict.
The full list, with the exemptions and the edge cases, is in 10%, 20% or 30% — which threshold applies.
What R-134a is made of
R-134a is a single HFC, not a blend. That composition is what decides coverage: 40 CFR 84.106 applies where the refrigerant contains a regulated substance, so a blend is caught by what is in it, not by its overall global warming potential.
The GWP test is a separate route into the rule, and it only applies to substitutes that are not regulated substances themselves. Alternatives listed at 40 CFR 84.64(b) with a GWP of 53 or below — R-290 propane at 3.3, R-717 ammonia at 1, R-744 carbon dioxide at 1, HFO-1234yf at 1 — are outside the leak repair requirements entirely. — 40 CFR 84.106(a), table 1 to 40 CFR 84.64(b)
If you are over the threshold
The clock starts on the day the refrigerant went in, not the day the calculation was done. Thirty days to find and repair — 120 if an industrial process shutdown is needed — an initial verification test inside that window, and a follow-up within ten days of the initial one passing. The 30-day repair clock and the two verification tests sets out the whole sequence.
Whether you are over or under, the calculation itself goes in the record, along with seven other things about that visit. What refrigerant records the EPA requires lists them.
One appliance is easy. A site full of them is not.
AirCert does this on every addition, on every unit
AirCert runs the leak rate every time refrigerant goes in, applies the right threshold for that appliance, starts the repair clock on the correct date, schedules both verification tests and prints the record. Out now on Android, and coming soon to iPhone and iPad.
Get it on Google PlayWhere this comes from
The leak rate definition and both formulas are at 40 CFR 84.102. Applicability, the thresholds and the repair deadlines are at 40 CFR 84.106. The global warming potentials for substitutes are in table 1 to 40 CFR 84.64(b). The EPA’s own summary is its January 2026 leak repair fact sheet.
This is a guide, not legal advice. Every figure is cited, but whether a particular appliance is covered, and which band it is in, depends on what it does and how it is used. Check the regulation, and take advice if the answer is not obvious.