Refrigerant leaks in HVACR equipment – particularly commercial refrigeration systems -- are a significant problem. According to the Environmental Protection Agency’s (EPA’s) GreenChill program, the typical supermarket has an annual leak rate of about 25 percent, which equates to about 1,000 lbs. of leaked refrigerant every year. That’s just for one store.

At a recent AHRI webinar, Rajan Rajendran, vice president, systems innovation center and sustainability at Emerson, noted that globally, more than half of the new refrigerant GWP that is produced goes straight into charging leaking equipment. That’s a shocking statistic.

While the voluntary GreenChill program has done a great job at helping participants reduce emissions -- with participating stores emitting at least 65% less refrigerant than the average supermarket -- too many others are not doing enough to find and repair leaks. To address this problem, EPA has been given broad authority under the AIM Act to not only phase down the production of high-GWP HFCs, but to reduce existing emissions from refrigerant leaks during use and at end-of-life.

We don’t yet know what EPA plans to do regarding refrigerant leaks, as they have until October to issue their final regulations. Remember, though, that in April 2020, EPA rescinded the leak repair provisions for appliances that contain substitute refrigerants, so it would not be surprising if EPA decided to reinstate some of those provisions.

With an increased focus on reducing emissions, as well the impending phase down of high-GWP HFCs, contractors will be called on more frequently to identify and repair the leaks experienced by their food retailer customers. That isn’t always an easy task, though, said Glenn Barrett, engineering manager at DC Engineering in Coeur d’Alene, Idaho, because some of the piping can’t be readily leak checked. That’s particularly true if it’s installed above a drop-in ceiling on the sales floor, underground, behind finished walls, or sandwiched between the roof deck and walk-in cooler or freezer box.

“There can be miles of copper piping in supermarkets, with connections every 20 feet (at a minimum) and at every fitting/transition, valve, filter, and sight glass. And, unfortunately, every connection carries the potential to leak refrigerant,” he said. “The typical refrigeration rack can have 100 or more connections and Schrader valves, and vibration propagated via the compressors can cause leaks as well. Refrigerant systems operate substantially above atmospheric pressure, so any small pin hole in a pipe or valve can become a substantial leak if not addressed immediately.”

However, some of these issues can be mitigated if the system is designed and operated correctly in the first place. Barrett said that the following best practices will go a long way to solving the industry-wide problem of refrigerant leaks:

  • Track and report leaks -- understand what is leaking, how much is leaking, and what patterns are found that can be addressed with technology or proper techniques;
  • Verify the correct leak was fixed and validate the amount of refrigerant added to the system matches the size of the leak fixed (may not be reasonable to assume a pin hole is responsible for leaking 500 lbs. of refrigerant). If not, there may be more than one leak source.
  • Obtain training on the correct use of state-of-the-art handheld refrigerant leak detection equipment and how to apply it;
  • Conduct regular periodic leak checks in the store and follow through to verify the leaks were addressed and by whom;
  • Design systems with smaller charges and natural refrigerants to lower the potential impact of catastrophic leaks;
  • Design systems with the shortest pipe lengths possible;
  • Define the costs associated with leaks for repair, refrigerant, efficiency, and product losses, then elevate those costs internally to gain visibility by top decision makers. Similar to how utility expenses are viewed, treat leaks as a controllable expense and take proven actions to reduce the amount of refrigerant lost;
  • Monitor receiver levels over time and perform leak checks when the trend shows a negative overall slope; and
  • Strengthen quality control procedures and verification before racks/cases/coils/condensing units and equipment leave the factory, ensuring they are as tight as possible (coils, racks, condensers, etc.).

“To move the needle in the positive direction with regards to leaks, the industry needs to place a larger focus on addressing leaks through training; holding each other accountable; implementing refrigeration systems with as small of a leak potential as possible; and making it a goal to find and fix all leaking systems,” said Barrett.

Very good advice that should be taken to heart by everyone who works on commercial refrigeration equipment.