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Reduce refrigerant leaks in supermarkets

Refrigerant leaks are a recurring problem, particularly in the commercial refrigeration sector. An American initiative aims to identify the main causes of leaks and to propose solutions to reduce them. 

The average annual leakage rate in a supermarket is estimated to be between 25 and 30% [1]. 

 

In the United States, the average supermarket contains about 1.6 tonnes of refrigerant. Leakage rates are therefore a major concern, as they have an impact on the energy efficiency of refrigeration systems, as well as on the environment.

 

The North American Sustainable Refrigeration Council (NASRC) recently launched an initiative to reduce leaks: six retailers are participating in this action. They have identified the top 10 leakage problems in refrigeration equipment and come up with specifications to improve refrigeration equipment and reduce leaks. 

 

Different causes of leaks have been identified, depending on their location: 

In cases and fixtures: 

  • Evaporator leaks due to tubing failures; 
  • Access valves; 
  • Lines rubbing together, either through contact/vibration or through thermal expansion; 
  • Electrical wiring failure. 

 

In machine rooms and racks: 

  • Compressor vibration  
  • High-side lines; 
  • Mechanical fitting connections; 
  • Tubing isolation from similar and dissimilar metals; 

 

In the condenser 

  • Tube sheet leaks  
  • Fan breakage/motors falling into the coil. 

 

People participating in the initiative have proposed best practices and are working on drafting the language for the specification:  

 

  • Require an operating pressure of 45 bar in devices and all compressor racks. 
  • Any tubing or part that carries refrigerant cannot come in contact with any other metal 
  • Eliminate mechanical threads for pipe fittings. 
  • Limit Rotolock fittings.  
  • Add a manometer or a temporary indicator to confirm that the circuit is pressurized.     
  • Regulating release valves 

 

Detecting and looking for the cause of the leak is an essential recommendation for reducing annual leak rates. If a leak detector is installed on the refrigeration equipment and a leak is found, the areas most likely to be the cause should first be examined: the pipe fittings and the compressor room are a good point starting point. 

 

Read the full article on ACHR News.

 

Read the IIR Informatory Note on the advancements in supermarket refrigeration, dealing among other things with refrigerant leaks. 

 

[1] The Environmental Protection Agency estimates the average annual leak rate at 25%. The IIR relies on figures from the AFCE, which put the average rate at 30%. 

https://iifiir.org/en/fridoc/refrigerant-containment-study-4677 (in French)