Question 1Leak repair rules
An office tower's R-22 chiller has a full charge of 200 lb. A technician adds 10 lb, 73 days after the last addition. What is the leak rate by the annualizing method?
Leak rate calculator
Enter the full charge and the refrigerant added, and get the annual leak rate by either method the rule allows, checked against the limit for the appliance type.
Work out a leak rate
30.4% a year
- Share of the charge added: 30 ÷ 400 = 0.0750.
- Share of a year: the shorter of 90 days or 365, so 90 ÷ 365 = 0.2466.
- Divide and turn into a percentage: 0.0750 ÷ 0.2466 × 100 = 30.4%.
Over the 20% limit.
Over 20 percent: the leaks must be found and repaired within 30 days of the refrigerant addition (120 days if an industrial process shutdown is needed), unless the owner chooses to retrofit or retire the appliance.
A certified technician finds the leaks with a leak inspection, and each repair is confirmed by an initial and a follow-up verification test.
The limits
| Appliance type | Limit a year |
|---|---|
| Commercial refrigeration Retail food and cold storage: supermarkets, restaurants, warehouses. | 20% |
| Industrial process refrigeration Process cooling linked to chemical, pharmaceutical, petrochemical or manufacturing work, industrial ice machines and ice rinks. | 30% |
| Comfort cooling and other appliances Air conditioning for occupied buildings, and any other appliance of 50 pounds or more. | 10% |
These limits apply to appliances with a full charge of 50 pounds or more of an ozone-depleting refrigerant, or a blend that contains one.
Try 3 test questions
Question 2Leak repair rules
A pharmaceutical plant cools a reaction vessel with a custom 900 lb R-22 system. What is its allowable leak rate?
Question 3Leak repair rules
A supermarket R-22 rack has a full charge of 400 lb. A technician adds 20 lb, 146 days after the previous addition. Under the annualizing method, does the leak repair rule require a repair?
Next step
Questions people ask
How do you calculate a refrigerant leak rate?
With the annualizing method, divide the pounds added by the full charge, divide that by the share of a year since the last addition (days over 365, at most 365), and multiply by 100. With the rolling average method, add up the pounds added over the last 365 days, divide by the full charge and multiply by 100. A facility uses the same method for all its appliances.
What are the allowable leak rates?
20 percent a year for commercial refrigeration, 30 percent for industrial process refrigeration, and 10 percent for comfort cooling and other appliances, for appliances with a full charge of 50 pounds or more of an ozone-depleting refrigerant.
What happens when an appliance is over the limit?
The owner must have the leaks found and repaired within 30 days of the refrigerant addition, or 120 days if an industrial process shutdown is needed, with an initial and a follow-up verification test; or plan to retrofit or retire the appliance.
Does it apply to R-410A systems?
This leak repair rule does not apply to appliances that hold only substitute refrigerants such as HFCs.