EPA Subpart C Leak Rate Calculator
Calculate system leak rates dynamically using the EPA annualized method. Under the AIM Act (40 CFR Part 84 Subpart C), the mandatory tracking threshold dropped from 50 lbs to 15 lbs on January 1, 2026.
Annualized leak rate calculations determine if a commercial refrigeration, comfort cooling, or industrial process system is leaking beyond statutory compliance limits.
Annualized Leak Rate Formula
Leak Rate % = (Lbs Added / Full Charge) * (365 / Days Since Last Addition) * 100
- 15 lb Threshold: Monitoring is required for all systems containing 15 lbs or more of HFC charge capacity.
- Leak rate thresholds: 10% for Comfort Cooling, 20% for Commercial Refrigeration, and 30% for IPR.
- Violation penalties: Failing to perform repairs within 30 days of exceeding thresholds can trigger statutory fines up to $69,733 per day, per violation.
Frequently Asked Questions
What is the EPA 15 lb refrigerant rule?
Under the EPA AIM Act (40 CFR Part 84 Subpart C), the mandatory leak rate tracking threshold was lowered from 50 lbs to 15 lbs on January 1, 2026. This means any comfort cooling or commercial refrigeration system containing 15 lbs or more of an HFC, or of a substitute with a GWP > 53, must be tracked for leak compliance. Ozone-depleting refrigerants such as R-22 are excluded from this rule by 40 CFR 84.106(a)(3)(i) and stay under 40 CFR Part 82 Subpart F, where the line is still 50 lbs.
What are the EPA leak rate thresholds in 2026?
The maximum allowable annualized leak rate thresholds under the EPA rules are: 10% for Comfort Cooling (comfort AC and heating systems), 20% for Commercial Refrigeration (food storage, supermarkets, cold lockers), and 30% for Industrial Process Refrigeration (IPR).
How is the annualized leak rate calculated?
The annualized leak rate is calculated using the following EPA-approved formula: Rate % = (Lbs Added / Full Charge) * (365 / Days Since Last Addition) * 100.
How long do I have to repair a leak that exceeds the threshold?
If a system exceeds the allowable leak rate threshold, the owner or operator has 30 days from the date of leak detection to locate and repair the leak, or 120 days where an industrial process shutdown is required. The repair must then be verified: an initial verification test within that same window showing the repair held, and a follow-up verification test within 10 days of the successful initial test or of the appliance returning to normal operating conditions. Further extensions are available under 40 CFR 84.106(f) in specific documented circumstances, such as a required component being unavailable.
Are residential AC systems exempt?
Yes, residential and light-commercial air conditioning and heat pump systems are generally exempt from the AIM Act leak repair rule (40 CFR 84.106). However, the app flags them conservatively for safety and compliance tracking.
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