How to stop refrigerant leaks before they start
Dramatic price increases along with a heightened concern for the environment continues to motivate change in operations strategies.
As the cost of refrigerant has increased dramatically during the past several years, leak detection, prevention and reducing refrigerant emissions have become a high priority for supermarkets, large chilling plants, food processing plants, cold storage facilities and large air conditioning installations. In order to do this, refrigerant management through effective leak detection and refrigerant tracking is essential.
Since 2017, the cost of hydrofluorocarbon (HFC) refrigerants has increased between 275-700%, especially in Europe with the FGas regulations based on the global warming potential (GWP) of these gases, according to Öko-Recherche, Germany. The older refrigerants with a high GWP are being gradually phased out in favor of newer compounds with a lower GWP. These newer compounds carry a CO2 equivalent much lower than the compounds they replace. As a result, refrigerant prices have skyrocketed over the past year, with this upward trend expected to continue worldwide.
Meanwhile, the cost of replacing refrigerants far outweighs the cost of the technician’s time to locate and repair these leaks. That doesn’t take into account the cost of lost inventory, increased utility consumption, damaged or overworked equipment and potential fines from regulators.
Dramatic price increases along with a heightened concern for the environment continues to motivate change in operations strategies. That’s why the goal of today’s refrigerant leak detection programs is to find small leaks before they become big problems.
Where do leaks typically occur?
The first question is, where do leaks typically occur in a commercial refrigeration system? Leaks often occur in mechanisms where there are changes in temperature, pressure and vibration. Valves, pipe joints and compressors are often the location where leaks can occur. Leaks can also be caused by poor installation or maintenances procedures aggravated by these changes. Any device that is poorly restrained or supported within the system can also cause leakage. In some instances, leaks can also be caused by unintentional damage by a third party such as cleaning machines, trucks or forklifts.
It is important to note that the majority of refrigerant loss is due to a number of small leaks that often exist for a very long time, making them more difficult to detect. In a study of several million leak events conducted by Bacharach, Madison, Va., it was discovered that leakage from mechanical joints tends to be progressive, starting small and working their way up to full-blown events. Leakage of refrigerant is often caused by a breakdown or failure of the equipment due to aging, resulting in failure of mechanical joints and seals. Aggravated by changes in temperature, pressure and vibration, some leaks come and go, making them very difficult and time-consuming to find.
Implementing a comprehensive leak detection program
With revised EPA Section 608 rules now in effect, it is also more important than ever to use a permanent leak detection system that ensures compliance with the latest regulations—or risk fines for failure to comply.
Refrigerant leaks are not only costly, but they can also be hazardous under certain conditions. ASHRAE Section 184.108.40.206 deals with safety of personnel who may be inadvertently exposed to harmful gases from a refrigerant leak. These developments have brought a new focus on a comprehensive refrigerant management strategy incorporating low level leak detection to the top of the agenda.
While most applications have some form of leak detection, the question now is whether the system is adequate. A proactive leak management program should include the correct type of leak detection technology coupled with a comprehensive remote monitoring and refrigerant tracking system to detect and notify personnel of leaks as early as possible. Each event is also weighted by its status—“Alert,” “Alarm” or “Critical.”
State-of-the-art systems include continuous monitoring with multi-party alerts that can be accessed from any location. The latest refrigerant management software can track events to determine patterns of which asset is typically the cause of the leak. The availability of this data can have a strong impact on the overall energy efficiency and effectiveness of the refrigeration system. The leak index acts as an early warning for a pending increased usage of refrigerant, while the leak rate defines the long-term performance of the system. The goal is to get and keep a low leak rate and to respond to leak events detected by the monitor quickly and effectively.
With today’s high cost of refrigerant, a proactive leak detection program has a significant impact on the bottom line. The average refrigerant leak rate for a grocery store is estimated to be about 25% per year, according to the GreenChill Partnership, a program run by the U.S. Environmental Protection Agency (EPA), Washington, D.C. A best practices implementation can reduce that rate to 7% per year. That means the return on investment can now be realized in a matter of months rather than years.
Selecting the right monitoring system
With various types of monitors on the market today, selecting the right monitor for the installation is a critical first step. These include infrared, semiconductor, electrochemical and catalytic bead options. The most sensitive and reliable type of monitor is infrared that can detect refrigerant gas leaks at 1 ppm. They can also be recalibrated to detect new gases as old ones are phased out and new refrigerants are introduced in the market.
For permanent monitoring, aspirated multi-point leak detection systems can continuously monitor up to 16 different locations across the refrigeration system, and for larger installations monitors, can be networked together. Also available are smaller monitors for less complex installations
As refrigerant prices continue to spiral upward and new environmental and safety regulations are introduced, the long-term success of the enterprise will no doubt call for a proactive refrigerant management program that can lower costs, reduce utility consumption and help protect the environment.