Blog

Oct 22, 2023

Reducing Refrigerant Leaks Is Industry Concern

LARGE BURDEN: For food retailers, refrigerant leaks represent a large financial

LARGE BURDEN: For food retailers, refrigerant leaks represent a large financial and operational burden, which is why it is important that they be found and fixed quickly. (Staff photo)

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%, and the average store contains about 3,500 pounds of refrigerant. Multiply that by thousands of stores across the U.S., and it's easy to see why leaks are such a big concern for end users, as well as the environment.

For food retailers, refrigerant leaks represent a large financial and operational burden, especially since the cost of refrigerants will likely be increasing in the near future due to the impending HFC phasedown. For the environment, leaks represent a large source of annual emissions; indeed, leaks in supermarkets across the U.S. may account for as much as 129 billion pounds of CO2e each year.

The North American Sustainable Refrigeration Council (NASRC) is addressing this issue through a leak reduction initiative that is being spearheaded by six of its retailer-members. Under this initiative, retailers identified the top 10 leak issues in refrigeration equipment and are developing equipment specifications that are designed to mitigate those leaks. In its recent online summit, NASRC offered details on some of those common sources of leaks and what causes them to occur.

According to Morgan Smith, program and communications director at NASRC, the top 10 leak issues identified by the retailers in the leak reduction initiative are:

In cases and fixtures:

In machine rooms and racks:

In the condenser:

As a response, the retailers in the initiative proposed the following best practices and are working on drafting the language for the specification:

Leia Waln, associate partner and program manager at Refrigerant Management Solutions, confirmed these major sources of leaks. She shared the details of a study of 100 supermarkets that showed that the largest number of leaks occur at the compressor racks, which accounted for 57% of all leaks. The second largest number of leaks occur within the display cases, which are out on the sales floor. These two locations comprise about 89% of leaks that occur in refrigeration systems, while 7% of the leaks occur in piping and 3% in remote condensers.

"In looking specifically at the components on a traditional compressor rack, the largest number of leaks occur on the compressors, with 28% of the overall leak locations occurring there, followed by leaks in the liquid line, suction line, receiver, and discharge line," she said. "The highest percentage of leak locations are on the suction service valve, followed by fittings, discharge service valve, discharge piping, liquid injection valve, and flanges/couplings."

Display cases account for 26% of the leaks, and the majority of these leaks occur in the evaporator, followed by the suction line and then the liquid line, said Waln. "If we look further into the data under the evaporator, we'd see that these leaks are mostly on the evaporator coils and the evaporator expansion devices."

While it is sometimes difficult to determine the root cause of a leak, Waln noted that for a traditional rack system, vibration is the main cause of leaks, followed by normal mechanical wear, seal failure, corrosion, gasket failure, and physical damage. The number one cause of leaks in display cases is corrosion, followed by normal mechanical wear, and vibration.

Finding — and fixing — leaks are key in reducing refrigerant emissions, and Clay Rohrer, director of connected solutions at Hussmann, offered the following comprehensive guidance on this subject:

"It's all about using detectors and data to focus and pinpoint the area and then confirming that the leak is fixed," said Rohrer. "If you don't confirm the fix, and if you don't have any refrigerant management tools in place, you're just constantly leaking. It's critical to constantly use data to continuously improve a site's leaks."

Joanna Turpin is a Senior Editor. She can be contacted at 248-786-1707 or [email protected]. Joanna has been with BNP Media since 1991, first heading up the company's technical book division. She obtained her bachelor's degree in English from the University of Washington and worked on her master's degree in technical communication at Eastern Michigan University.