LeakLedgerPart 84 guide
How to Determine Full Charge Under Part 84: The Four Methods
Every Part 84 number starts with the full charge. It decides whether an appliance is covered at all, it is the denominator of every leak rate, and it sets the inspection schedule and the chronic-leak test. The rule gives four ways to determine it — and since January 1, 2026, owners must have it on record for every appliance with 15 lb or more (40 CFR 84.106(l)(1)). Here's how each method works and what to write down.
What “full charge” means
Part 84 defines full charge as the amount of refrigerant required for the appliance's normal operating characteristics and conditions, determined using one — or a combination — of four methods (§84.102):
- The equipment manufacturer's determination of the full charge.
- Appropriate calculations based on component sizes, density of refrigerant, volume of piping and other relevant considerations.
- Actual measurements of the amount of refrigerant added to or evacuated from the appliance, including for seasonal variances.
- An established range based on the best available data about the appliance's normal operating characteristics and conditions — where the midpoint of the range serves as the full charge.
Why it matters so much
The same number is used five different ways:
- Coverage. Leak repair applies to appliances with a full charge of 15 lb or more of an HFC or a substitute with GWP above 53 (§84.106(a)). See does the 15-lb rule apply to my equipment.
- Leak rate. Both calculation methods divide pounds added by the full charge (§84.102). See annualizing vs rolling average.
- Inspection schedule. After a repair, commercial and industrial process refrigeration at 500 lb or more is inspected quarterly; smaller systems once a year (§84.106(g)).
- Chronic leakers. An appliance that leaks 125% or more of its full charge in a calendar year must be reported by March 1 (§84.106(j)). See the March 1 report.
- Automatic leak detection. Commercial and IPR systems with 1,500 lb or more need ALD, which must alert at a loss of 50 lb or 10% of the full charge, whichever is less (§84.108(a), (g)). See the ALD requirement.
Same addition, different answer
Take a supermarket rack that needed 40 lb over the last 365 days, using the rolling average method:
| Full charge on record | Leak rate | Against the 20% threshold |
|---|---|---|
| 175 lb | 40 ÷ 175 = 22.9% | Over — 30-day repair clock starts |
| 210 lb | 40 ÷ 210 = 19.0% | Under |
A full charge that is too high hides leaks; one that is too low starts repair clocks for nothing. Either way, the method behind the number has to hold up if anyone asks how it was determined.
Choosing a method in practice
- Self-contained and packaged equipment: the nameplate or manufacturer data (method 1) is usually the simplest and most defensible.
- Field-piped racks and split systems: the factory charge covers only part of the system. Combine the manufacturer's figure for the condensing unit with calculations for line sets, cases, coils and receivers (methods 1 and 2).
- Systems with a known service history: pounds recovered during a full evacuation, or charged into an empty system, are actual measurements (method 3).
- Systems whose charge legitimately moves with load or season: an established range from the best available data (method 4), with its midpoint as the full charge.
What the owner must keep
By January 1, 2026 — or at installation for appliances installed after that — owners or operators must determine the full charge of every appliance with 15 lb or more and keep, until three years after the appliance is retired (§84.106(l)(1)(i)–(vi)):
- The identity of the owner or operator, and the address where the appliance is located
- The full charge, and the method used to determine it
- For method 4: the range, its midpoint, and how the range was determined
- Any revisions of the full charge, how they were determined, and the dates they occurred
- The date of installation
The full charge also appears on every service record (§84.106(l)(2)(vii)) and in any extension request, retrofit or retirement plan, or relief request, together with the method used to determine it (§84.106(f), (h), (i)).
When the full charge changes
Adding cases to a rack, re-piping, or replacing a condenser changes the charge. Record a revision with the new figure, how it was determined and the date — and don't rewrite the old figure: leak rates calculated before the change used it, and the history should show why the numbers moved.
A contractor's checklist
- Photograph the nameplate on every visit to a new appliance.
- For field-piped systems, keep the calculation: line lengths and sizes, case and coil volumes, receiver level.
- Note recovered and charged pounds in words on full evacuations (“recovered 186 lb, system empty”).
- Write the method next to every full charge you hand a customer — method 1, 2, 3 or 4.
LeakLedger stores the full charge for each appliance with its method, uses the midpoint of a method-4 range unless you enter a figure inside it, keeps every revision with its date, method and who made it, and tells you which full charge its leak rates use. Try the math yourself with the leak rate calculator, or read the complete Part 84 guide.
Decision support, not legal advice. Where your situation is unclear, confirm with your compliance advisor.
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This guide summarizes 40 CFR 84.102, 84.106 and 84.108 as published in the eCFR. It is not legal advice; where the rule is unclear we say so. Read the rule: 40 CFR Part 84, Subpart C.