This refrigerant types guide explains the gases techs are seeing in racks, rooftop units, condensing units, ice machines, cold rooms, and industrial plants in 2026. You will know where each refrigerant fits, what safety class it carries, and which skills make you more valuable on service calls.
Commercial refrigeration is splitting into three lanes.
Legacy HFC systems still run everywhere. R-410A, R-404A, R-407A, R-448A, and R-449A remain in supermarkets, restaurants, warehouses, and light commercial HVAC equipment. The work is not disappearing. Leak repair, recovery, reclaim, compressor swaps, and retrofit support still pay.
A2L equipment is moving into new air conditioning, heat pumps, and some light commercial applications. R-454B and R-32 are the two names techs keep hearing because they replace R-410A in many new systems. EPA’s AIM Act HFC phasedown reduces HFC production and consumption to 15% of historic baseline levels by 2036, and the 2024 through 2028 allocation step sits at 60% below baseline. That pressure is why A2L refrigerants are showing up now.
Natural refrigerants are growing in food retail, cold storage, and industrial refrigeration. R-744, R-717, and R-290 are not new, but their job value is climbing because they meet low-GWP requirements without waiting for the next synthetic blend.
| Refrigerant | Common name | Safety class | GWP | Main field use | Tech note |
|---|---|---|---|---|---|
| R-410A | HFC blend | A1 | 2,088 | Older and current AC, heat pumps, light commercial | High pressure, phasedown pressure, still serviced |
| R-454B | HFO/HFC blend | A2L | 465 | New AC, heat pumps, some light commercial | Mildly flammable, R-410A replacement |
| R-32 | HFC | A2L | 675 | New AC, heat pumps, packaged equipment | Single component, mildly flammable |
| R-744 | CO2 | A1 | 1 | Supermarkets, cold storage, cascade and transcritical systems | Very high pressure, different controls mindset |
| R-717 | Ammonia | B2L | Near 0 | Industrial plants, cold storage, food processing | Toxicity drives procedures and response |
| R-290 | Propane | A3 | Very low, often listed near 3 | Self-contained cases, reach-ins, small commercial equipment | Highly flammable, small charges, no shortcuts |
ASHRAE Standard 34 assigns refrigerant numbers and safety classifications based on toxicity and flammability data. A1 means lower toxicity and no flame propagation. A2L means lower toxicity and lower flammability. A3 means higher flammability. B2L means higher toxicity and lower flammability.
EPA’s technology transition rule lists R-32 at GWP 675, R-454B at GWP 465, and R-744 at GWP 1. Those numbers explain why R-410A is losing new-equipment share.
R-410A is the refrigerant every commercial HVAC tech knows. It replaced R-22 in many air conditioning and heat pump systems, and it runs at higher pressures than R-22. It is an A1 refrigerant, so it is lower toxicity and nonflammable under ASHRAE classification.
The problem is GWP. R-410A has a 100-year GWP of 2,088. That puts it on the wrong side of the HFC phasedown, even though existing systems still need service. New equipment is moving away from it because manufacturers need lower-GWP refrigerants to meet EPA rules.
For techs, R-410A still matters for income. Expect years of work on leak checks, coil replacements, compressor changeouts, recovery, evacuation, and charging. Do not treat R-410A as dead. Treat it as a service refrigerant with rising reclaim value and tighter supply discipline.
The career move is simple: keep your R-410A service fundamentals sharp, but add A2L training before your employer forces the issue.
R-454B is one of the main A2L replacements for R-410A in new air conditioning and heat pump equipment. It has a much lower GWP than R-410A, with EPA listing it at 465. It is mildly flammable, so the service routine changes.
R-454B is not a drop-in refrigerant for existing R-410A systems. New equipment uses different labeling, safety controls, charge limits, installation instructions, and service procedures. You follow the nameplate and manufacturer literature, not pressure habits from older equipment.
A2L work requires specific jobsite discipline:
The techs who get comfortable with R-454B early will take more startup, warranty, and commissioning work in 2026.
R-32 is another major A2L refrigerant replacing R-410A in new equipment. EPA lists R-32 at GWP 675. That is higher than R-454B but far below R-410A.
R-32 is a single-component refrigerant, not a zeotropic blend. That helps with charging and composition stability. It still requires A2L procedures because it is mildly flammable.
For commercial techs, R-32 shows up most in packaged HVAC, heat pump, and light commercial equipment. The service work looks familiar until you hit the safety requirements. You still diagnose airflow, metering devices, compressor operation, reversing valves, boards, sensors, and charge. The difference is the risk control around recovery, leak detection, ventilation, and hot work.
Do not mix R-32 habits with R-410A habits. Cylinder fittings, labeling, recovery process, and manufacturer instructions matter. A tech who treats every blue or gray cylinder the same will create problems.
R-744 is carbon dioxide. It has a GWP of 1 and an A1 safety classification, which means lower toxicity and no flame propagation under ASHRAE classification. It is common in supermarket refrigeration, cold storage, cascade systems, and transcritical CO2 racks.
CO2 is not “easy” just because it is nonflammable. The pressure changes the whole service mindset. Standstill pressure, pressure relief valves, gas coolers, flash gas bypass, ejectors, parallel compression, and high-pressure controls matter. A careless valve-off or trapped liquid condition creates a serious hazard.
CO2 work rewards techs who read schematics and understand controls. You need to know how medium-temp and low-temp loads interact, how the rack manages pressure, and how ambient temperature affects transcritical operation.
For career growth, R-744 is one of the best refrigerant types to learn. Supermarkets and cold storage operators need techs who troubleshoot racks, not just swap parts.
R-717 is ammonia. It dominates industrial refrigeration in food processing, cold storage, breweries, dairies, ice plants, and distribution facilities. It has excellent heat transfer properties and very low climate impact, but it carries a B2L safety classification because toxicity drives the risk profile.
Ammonia work is a different trade lane from light commercial HVAC. You deal with vessels, pumps, evaporators, condensers, compressors, oil pots, relief systems, machine rooms, detection systems, ventilation, and written operating procedures.
OSHA’s Process Safety Management standard applies to ammonia refrigeration systems containing 10,000 pounds or more of ammonia. That threshold changes the paperwork, training, mechanical integrity, process hazard analysis, and operating procedure requirements around the system.
The pay upside comes from responsibility. Ammonia techs handle bigger systems, higher production risk, and stricter safety programs. If you want industrial refrigeration jobs, learn P&IDs, IIAR practices, lockout procedures, emergency response, and compressor teardown basics.
R-290 is propane. It is an A3 refrigerant, which means lower toxicity but higher flammability. EPA SNAP rules allow R-290 in specific refrigeration and air conditioning end uses subject to use conditions. EPA’s SNAP Rule 26 fact sheet discusses R-290 use in new self-contained commercial ice machines and stand-alone equipment.
You see R-290 in reach-ins, prep tables, merchandisers, beverage coolers, ice machines, and other self-contained commercial equipment. Charge sizes are small, but the flammability risk is real. Do not braze into a charged or contaminated circuit. Do not use standard practices from A1 refrigerants and assume the small charge protects you.
R-290 service is about clean process. Confirm the charge, recover or vent only as allowed by regulation and procedure, ventilate the space, use spark-safe equipment, and follow the manufacturer’s service bulletin. Many R-290 repairs are sealed-system jobs in tight kitchens with poor access. That makes discipline more important, not less.
The A2L transition is not a future topic. It is already in purchasing, installation, warranty, and service departments. Federal Register material from 2025 noted that, while systems using other refrigerants such as R-410A could be installed until January 1, 2026, market data showed most systems being sold were using R-454B or R-32. It also noted A2L cylinder supply issues in 2025.
That means employers need techs who understand both sides of the transition. They need someone who can service an older R-410A rooftop unit at 8 a.m. and start up an R-454B unit after lunch.
Your 2026 training checklist should include:
BLS reported a median annual wage of $59,810 for heating, air conditioning, and refrigeration mechanics and installers in May 2024, with 8% projected employment growth from 2024 to 2034. Techs who handle newer refrigerant types, rack systems, and industrial safety programs position themselves above the basic median.
Start with the equipment you already touch.
If you work commercial HVAC, learn R-410A, R-454B, and R-32 first. That covers older service calls and the new A2L equipment replacing R-410A.
If you work restaurants and convenience stores, learn R-290 next. Small self-contained equipment is everywhere, and owners hate downtime on prep tables, merchandisers, and ice machines.
If you want supermarket work, learn R-744 CO2 and the HFC blends used in existing racks. CO2 gets you into newer stores and higher-skill troubleshooting.
If you want industrial refrigeration, learn R-717 ammonia. That path requires safety discipline, documentation, and comfort around large mechanical systems.
The best techs do not chase every refrigerant at once. They build a stack. First, handle today’s calls safely. Second, learn the refrigerant showing up in tomorrow’s installs. Third, specialize in the systems that pay more because fewer techs understand them.
This refrigerant types guide comes down to one point: refrigerant knowledge now separates average techs from valuable techs. R-410A keeps the service market busy, R-454B and R-32 drive the A2L transition, R-744 is growing in commercial racks, R-717 anchors industrial refrigeration, and R-290 owns a growing share of small self-contained equipment.
The tech who understands pressure, safety class, GWP, charge limits, recovery, leak detection, and manufacturer procedure will get the better calls.
Ready to work on the systems using these refrigerant types? Check the commercial refrigeration jobs feed on Fridgejobs.com and look for roles that mention A2L, CO2, ammonia, supermarket racks, industrial refrigeration, or R-290 service.