Still, adjustments are necessary. Most electronic tools, gauges, and testing equipment must be rated for use with flammable refrigerants, noted Summers, in order to eliminate the risk of sparks during operation. For instance, A2L refrigerants must only be recovered with machines designed and certified for that refrigerant type.  

Adam Ciesielski, director of engineering at Zero Zone, agreed, noting that A2L-rated service tools and equipment are necessary to ensure compliance and safety.   

“Technicians will also need to evaluate and become compliant with A2L regulations and standards, which govern system design, charge limits, and ventilation requirements.”  

Another key difference between A1 and A2L installations is the need to install safety shut-off valves, said Vince Zolli, P.E., general manager and vice president of engineering at KeepRite Refrigeration.  

“It’s also crucial to follow best practices for brazing, including purging with an inert gas.”  

In addition, brazing should never be done on a charged system, noted Summers, and technicians should always work in a well-ventilated service area as a precaution against potential refrigerant leaks. He added that “only A2L trained and qualified personnel should service or install the equipment.”  

Leak Detection

Perhaps the most noticeable change for contractors working on A2L systems will be the introduction of new leak detection and mitigation controls. Trenton Yule, application engineer at Danfoss, noted that HVAC systems charged with more than 4 pounds of A2L refrigerant require A2L-compatible leak detectors under UL 60335-2-40, the safety standard for heating and cooling equipment.  

“The A2L sensors must tie into unit control and automatically shut off the compressor and activate the indoor blower fan to dilute refrigerant concentrations by circulating air,” he said. “To minimize ignition risk, potential ignition sources such as electric resistance heaters must be de-energized.”  

These new features represent a cultural shift as much as a technical one.   

“As these new sensors were not found in units prior to A2L adaptation, there will be a learning curve in familiarity with gas sensors and the different technologies utilized in different sensors,” added Yule. “There is also a learning curve in how they interact with the unit controls to mitigate any potential leak situations. It will take time to become familiar with these new control schemes.”  

Ciesielski added that some A2L commercial refrigeration system layouts may also feature isolated refrigerant segments to limit the releasable charge if a leak occurs, improving containment and control. He stressed that leak detection isn’t just about initial installation — it’s also about ongoing upkeep.  

“Leak detection systems must be installed in areas where refrigerant leaks are possible, such as mechanical rooms and display cases,” said Ciesielski. “Additionally, contractors should be prepared for the long-term maintenance of leak mitigation systems, which are essential for sustaining safe operation over the life of the equipment.”  

Room Size Requirements  

As previously noted, system design considerations will change with A2Ls. According to David Bolanos, director of product management and marketing at Heatcraft, the new requirements rely on the concept of minimum room size.  

“One of the main differences of A2Ls vs. HFC/HFOs included in UL 60335-2-89 (the safety standard for commercial refrigeration equipment) and ASHRAE 15 (the safety standard for all refrigeration and air conditioning systems) addresses minimum room areas called A(min), which have a unit of measure of square-footage,” he said. “They specifically limit the installation of A2L indoor equipment to minimum room areas, depending on the specific A2L refrigerant used.”  

For commercial refrigeration manufacturers, this means they are required to calculate A(min) for each indoor equipment model and label each indoor unit model with its calculated number (the internal square footage dimension of the refrigerated space), said Bolanos.  

“The implication is that anyone who participates in the design, equipment selection, and servicing of refrigeration systems in walk-in freezers and coolers (WICF) will be required to know this new equipment attribute,” he said. “The attribute is critically important when replacing existing HFC equipment to make sure that the new A2L indoor equipment complies with the A(min) UL requirement for the WICF.”  

The transition to A2L refrigerants may feel like a big change, but with the right tools, training, and awareness, contractors can adapt smoothly — and keep safety front and center.