The refrigerant inside your HVAC system determines its efficiency, environmental impact, service costs, and future serviceability. In 2026, the residential HVAC market has largely transitioned from R-410A (GWP 2,088) to R-32 (GWP 675) and R-454B (GWP 466) — but millions of homes still run systems charged with R-22 or R-410A, and understanding the differences matters for maintenance decisions, replacement planning, and your wallet.
This guide covers every refrigerant you'll encounter in residential and light commercial HVAC: what it is, how it works, where it's used, and what it means for you as a homeowner or building operator.
How Refrigerants Work: A 60-Second Primer
Before comparing specific types, it helps to understand what refrigerant actually does. A refrigerant is a chemical compound that cycles between liquid and gas states at temperatures useful for heating and cooling. The basic cycle works like this:
- Evaporator (indoor): Liquid refrigerant absorbs heat from your indoor air as it evaporates into a gas. This cools your home.
- Compressor: The gas is compressed, which raises its temperature and pressure significantly.
- Condenser (outdoor): The hot, high-pressure gas releases heat to the outdoor air as it condenses back into a liquid.
- Expansion valve: The liquid's pressure drops, cooling it down before it enters the evaporator again.
The specific refrigerant used affects every step: how much heat it can absorb per pound, what pressures the system operates at, what temperatures it can reach, and how efficiently the compressor can do its job. It's not just a generic "coolant" — it's the working fluid that defines the system's fundamental performance.
Understanding the "R" Numbering System
HVAC refrigerants follow a systematic naming convention defined by ASHRAE Standard 34. The "R" stands for "Refrigerant," and the numbers encode the molecular composition. For single-component refrigerants, the numbering follows a formula based on carbon, hydrogen, and fluorine atoms. For blends, the 400-series (like R-410A) indicates zeotropic mixtures, while the 500-series indicates azeotropic mixtures.
You don't need to memorize the chemistry. What matters is knowing which refrigerant is in your system (check the unit's data plate), whether it's still being produced, and what that means for service costs.
The Master Comparison Table
R-22 (HCFC-22, "Freon"): The Legacy Refrigerant
What It Is
R-22 (chlorodifluoromethane, CHClF2) is a hydrochlorofluorocarbon that was the standard residential HVAC refrigerant from the mid-1990s through 2010. "Freon" is technically a brand name from DuPont (now Chemours), but it became the generic term for R-22.
Why It Was Phased Out
R-22 has an ozone depletion potential (ODP) of 0.055. The chlorine atom in its molecule contributes to stratospheric ozone destruction. Under the Montreal Protocol and the U.S. Clean Air Act, the phase-out proceeded as follows: production caps began in 2004, new R-22 equipment was banned in 2010, and all production and import was banned in 2020.
Current Status (2026)
R-22 is available only from reclaimed and recycled supply. Certified reclaimers (A-Gas, Hudson Technologies, National Refrigerants) recover R-22 from decommissioned systems, purify it to AHRI Standard 700, and resell it.
Current pricing runs $50-100+/lb wholesale, with retail service pricing often reaching $100-150+/lb including labor. A full recharge for a typical 3-ton R-22 system (6-12 lbs) can cost $600-1,800 in refrigerant alone.
How to Identify an R-22 System
Check the data plate on your outdoor condenser unit. It will list the refrigerant type. If your system was installed between approximately 1995 and 2010, it likely uses R-22. Common indicators include: the data plate says "R-22" or "HCFC-22," the system uses 3/8" suction line (R-410A typically uses 3/4" for similar capacity), and low-side operating pressures around 60-80 psi in cooling mode (R-410A runs at 115-130 psi).
If you still have an R-22 system in 2026: Replace it. These systems are 16+ years old at minimum, running on expensive reclaimed refrigerant, and operating at SEER ratings of 8-13 — far below modern systems at SEER2 15-22+. Every year you delay costs you money in both refrigerant and electricity. A single emergency R-22 recharge can cost more than 15% of a new system.
Real-world example: The Chen family in Atlanta had a 2006 Trane R-22 system. Over their last 3 years of ownership, they spent $2,400 on R-22 (three leak repairs and recharges) plus $1,600 in other repairs. Their summer electric bills averaged $340/month. After installing a 17 SEER2 R-32 heat pump ($9,800 installed minus $2,000 federal tax credit = $7,800 net), their summer bills dropped to $220/month. Between energy savings ($1,440/year) and eliminated R-22 costs (~$800/year), the payback period was 3.5 years.
R-410A (HFC-410A, "Puron"): The Outgoing Standard
What It Is
R-410A is a near-azeotropic blend of R-32 (50%) and R-125 (50%). Carrier branded it "Puron" when introducing it as R-22's replacement. It became the dominant residential refrigerant from the early 2000s through 2024 and is found in the vast majority of currently operating HVAC systems.
R-410A was revolutionary for its time: zero ozone depletion, higher efficiency than R-22, and excellent performance in scroll compressor designs that dominated residential HVAC. It enabled the jump from SEER 10-13 systems to SEER 16-21+ equipment.
Why It's Being Phased Out
R-410A's GWP of 2,088 makes it nearly three times over the EPA's new limit of 700 GWP for residential HVAC equipment. The AIM Act's phase-down schedule progressively reduces R-410A production through 2036. New residential equipment using R-410A has been banned since January 1, 2026.
Ironically, R-410A is 50% R-32. By removing the R-125 component (GWP 3,500), you get R-32 — a refrigerant with one-third the climate impact and better thermodynamic properties. The industry is essentially stripping out the high-GWP half of a blend it already knows well.
Current Status and Pricing Outlook
R-410A remains available for servicing existing equipment. Current 2026 pricing runs $8-15/lb, but prices are projected to rise significantly through the AIM Act phase-down. By the 2029 step (60% cumulative reduction), expect $20-35/lb. By 2034-2036, prices could reach $50-100+/lb, mirroring the R-22 phase-out trajectory.
Identifying Your R-410A System
Any residential HVAC system installed between approximately 2006 and 2024 almost certainly uses R-410A. The data plate will read "R-410A" or "Puron." Key characteristics include: larger suction line diameter (typically 3/4" for 2-3 ton systems), higher operating pressures (low side around 115-130 psi, high side around 350-420 psi in cooling mode), and the system likely has a SEER rating between 13 and 21+.
For R-410A owners in 2026: Don't panic. Your system is legal to operate and service. Prioritize annual maintenance with leak checks to minimize refrigerant loss. Start planning replacement when the system reaches 12-15 years of age or when a major component fails. Proactive replacement during the off-season (fall or spring) saves 10-20% compared to emergency summer replacement.
R-32 (HFC-32): The New Standard
What It Is
R-32 (difluoromethane, CH2F2) is a single-component HFC that has become the primary R-410A replacement globally. It's not new chemistry — it's half of R-410A — but using it as a standalone refrigerant unlocks significant performance and environmental advantages.
Daikin pioneered R-32 in residential mini-splits in Japan in 2012 and waived its R-32 equipment patents in 2015 to accelerate global adoption. Over 200 million R-32 units now operate worldwide, providing a massive real-world dataset confirming its safety and performance.
Technical Advantages Over R-410A
R-32 outperforms R-410A on several key metrics that translate to real benefits for homeowners:
Higher efficiency: 3-5% better COP at standard conditions, increasing to 7-12% at extreme outdoor temperatures (105°F+). In hot climates like Arizona or Texas, R-32 systems deliver measurably better cooling performance when you need it most.
Lower charge requirement: 25-30% less refrigerant needed for equivalent cooling capacity. A 3-ton R-410A system typically holds 7-10 lbs; the equivalent R-32 system needs just 5-7 lbs. Less refrigerant means lower leak potential, lower environmental impact, and lower recharge costs.
Better heat pump performance: R-32's higher compressor discharge temperatures — initially seen as a drawback — actually improve heating mode performance. R-32 heat pumps can deliver adequate heating at lower outdoor temperatures before needing electric backup heat, which is a significant advantage in cold climates.
Simpler service: As a pure compound, R-32 doesn't experience "fractionation" — the composition change that occurs when a blend like R-410A leaks. With R-410A, a leak can change the remaining refrigerant's composition, degrading performance and complicating recharging. R-32 eliminates this problem entirely.
The A2L Safety Classification
R-32 is classified A2L — "lower flammability." This is the single biggest talking point in the refrigerant transition, and it deserves a clear, data-driven discussion.
What A2L means in practice: R-32 can, under very specific laboratory conditions, be ignited. However, the conditions required are so extreme that real-world ignition risk is negligible. You need a concentration of 14.4% in air (a massive, sustained leak in a sealed room), an ignition source delivering 30-100+ millijoules of energy (a standard household light switch produces about 1-2 mJ), and even then, it burns at less than 10 cm/s — about as fast as a candle flame spreading across a piece of paper.
For context, natural gas — which runs through pipes in millions of homes — ignites at 0.28 mJ (100-400 times less energy than R-32) and has a flammability limit of just 5% in air (nearly 3x easier to reach than R-32). If you're comfortable with a gas stove, a gas furnace, or a gas water heater, R-32 represents a categorically lower ignition risk.
Modern R-32 equipment includes multiple engineered safety layers: built-in refrigerant leak sensors in indoor units, automatic system shutdown at low concentrations (typically 25% of LFL), charge limits calculated based on room volume per UL 60335-2-40, and spark-resistant electrical components near refrigerant connections.
Real-world example — R-32 in tight spaces: A homeowner in a 900 sq ft New York City apartment installed a Daikin 15,000 BTU R-32 wall-mounted mini-split in the bedroom. The system charge is 2.4 lbs. Even if the entire charge leaked instantly into the 120 sq ft bedroom with the door closed and no ventilation (an extreme worst-case scenario), the resulting concentration would be approximately 3.8% — well below the 14.4% lower flammability limit. The unit's built-in sensor would trigger shutdown and alarm at approximately 0.9% concentration, long before any flammability risk.
R-32 Manufacturer Adoption (2026)
R-32 is used by: Daikin (all residential lines), Goodman/Amana (Daikin subsidiaries), Fujitsu (all residential), Mitsubishi Electric (all mini-splits), Midea/Mr. Cool (all residential), Gree (all residential), LG (most residential), and Samsung (most residential). It commands roughly 55-60% market share in new residential installations and 80%+ in ductless mini-splits.
R-454B (Opteon XL41): The Low-GWP Blend
What It Is
R-454B is a zeotropic blend of R-32 (68.9%) and R-1234yf (31.1%), developed by Chemours and sold under the brand name Opteon XL41. Several major U.S. manufacturers chose R-454B as their primary R-410A replacement for ducted residential systems.
Technical Characteristics
R-454B's GWP of 466 is 30% lower than R-32 (675) and 78% lower than R-410A (2,088). Its operating pressures are closer to R-410A, which allows some manufacturers to adapt existing R-410A system designs with fewer engineering changes. This ease of transition was a major factor in its adoption by Carrier, Trane, and Lennox.
The trade-offs compared to R-32: R-454B has approximately 5-8% lower volumetric cooling capacity, it requires charge sizes similar to R-410A (no 25-30% reduction), and as a blend, it experiences temperature glide (~1.5 degrees C) and potential fractionation during leaks. The temperature glide complicates leak detection because the remaining charge's composition shifts, and topping off a leaked system may not restore proper operation — you may need to recover the remaining charge and recharge from scratch.
Bottom line for homeowners: Whether your new system uses R-32 or R-454B, the practical performance difference is small. Focus on the overall system quality, SEER2 rating, installation quality, and warranty terms rather than which specific low-GWP refrigerant the manufacturer chose. Both are safe, efficient, and compliant.
R-454B Manufacturer Adoption (2026)
R-454B is used by: Carrier (most ducted residential lines), Trane (many ducted residential models), Lennox (most residential lines), and Rheem/Ruud (most ducted products). It commands roughly 30-35% of the new residential HVAC market.
R-290 (Propane): The Natural Refrigerant
What It Is
R-290 is simply propane (C3H8) — the same chemical used in barbecue grills and portable heaters. It's classified as a "natural refrigerant" because it exists naturally in the environment, unlike synthetic HFCs and HCFCs.
With a GWP of just 3, R-290 has an almost negligible climate impact. Its thermodynamic properties are excellent for air conditioning, and it's been used in commercial refrigeration (especially in Europe) for years.
Why It's Gaining Traction
R-290 solves the GWP problem completely — at GWP 3, it's future-proof against any foreseeable tightening of regulations. It's also cheap, widely available, and performs well thermodynamically.
In the U.S., UL updated its standards in 2023 to allow R-290 in self-contained HVAC equipment with up to 300g (~10.6 oz) charge — enough for window ACs up to about 16,000 BTU/h and portable ACs. Several manufacturers now offer R-290 window units, and the EPA's Technology Transitions Rule includes R-290 as an approved alternative.
The Safety Consideration
R-290 is classified A3 — highly flammable. Unlike R-32's mild flammability, propane's flammability is real and well-documented: low ignition energy (0.25 mJ), low flammability limit (2.1% in air), and fast burning velocity (40+ cm/s).
This limits R-290's use to small, self-contained, factory-sealed systems where the total charge is strictly controlled. You won't see R-290 in large ducted split systems or VRF installations. Its role is in window ACs, portable ACs, small dehumidifiers, and potentially future small-capacity self-contained heat pumps.
Global perspective: Europe already permits R-290 in split-system air conditioners with charges up to 988g under updated IEC 60335-2-40 standards. Several European manufacturers offer R-290 mini-splits. The U.S. may eventually follow, but current UL standards restrict R-290 to self-contained equipment. If you see an R-290 split system marketed in the U.S., verify it meets current UL and local code requirements.
Other Refrigerants You Might Encounter
R-134a (HFC-134a)
GWP: 1,430. Used primarily in automotive AC, medium-temperature commercial refrigeration, and centrifugal chillers. Not common in residential HVAC. Being phased down in automotive applications in favor of R-1234yf (GWP 4).
R-1234yf (HFO-1234yf)
GWP: 4. An HFO (hydrofluoroolefin) that's the standard automotive AC refrigerant replacement for R-134a. It's also a component of R-454B (31.1%). Excellent GWP profile but expensive and not used as a standalone refrigerant in residential HVAC due to its lower cooling capacity and high cost.
R-407C
GWP: 1,774. A blend (R-32/R-125/R-134a at 23/25/52%) that was used as an R-22 replacement in some commercial and international residential applications. It has significant temperature glide (~7 degrees C) and is being phased out alongside other high-GWP HFCs.
R-404A
GWP: 3,922. Used in commercial refrigeration (supermarket cases, cold storage). One of the highest-GWP refrigerants in common use and a primary target of AIM Act reductions. Being replaced by R-448A, R-449A, R-454C, CO2, and propane in commercial refrigeration.
R-513A
GWP: 631. A non-flammable (A1) blend of R-1234yf and R-134a used primarily in centrifugal chillers. It's notable as one of the few low-GWP options that maintains A1 (non-flammable) classification, making it popular for large commercial chillers where the A2L classification creates installation complexity.
R-744 (CO2)
GWP: 1. Carbon dioxide used as a refrigerant in transcritical cycles, primarily for commercial refrigeration and heat pump water heaters (very popular in Japan as "Eco Cute" systems). Operates at very high pressures (1,000+ psi) requiring specialized components. Emerging in commercial applications but not yet practical for residential HVAC in most markets.
How to Identify the Refrigerant in Your System
Finding out what refrigerant your system uses takes about 30 seconds:
Step 1: Go to your outdoor unit (condenser/heat pump).
Step 2: Find the data plate — usually a metal or plastic label on the side or back panel. It may also be inside the access panel.
Step 3: Look for "Refrigerant Type," "Charge," or "Factory Charge" on the label. It will say something like "R-22," "R-410A," "R-32," or "R-454B," along with the charge amount in pounds and ounces.
Step 4: If the label is worn or illegible, search the model number online — manufacturer spec sheets always list the refrigerant type.
The Environmental Generation Gap: Comparing Impact Across Eras
To appreciate how far refrigerant technology has come, consider the lifetime environmental impact of equivalent 3-ton cooling systems across refrigerant generations:
Real-world example — generational leap: A 2005-vintage R-22 system cooling a 2,000 sq ft home in Houston uses approximately 5,500 kWh per cooling season at SEER 11. The same home with a 2026 R-32 system at SEER2 18 uses approximately 2,800 kWh — saving over $300/year in electricity at Houston rates. Add the 69% reduction in refrigerant climate impact, and the 2026 system has roughly half the total environmental footprint.
Choosing Between R-32 and R-454B Systems: A Buyer's Guide
If you're shopping for a new HVAC system in 2026, you'll encounter both R-32 and R-454B options. Here's a practical decision framework:
Choose R-32 if:
- You're installing a ductless mini-split (R-32 dominates this market)
- You want maximum efficiency, especially in hot climates
- You prefer the simplicity of a pure compound (easier service, no fractionation)
- Your preferred manufacturer (Daikin, Fujitsu, Mitsubishi, Goodman, etc.) uses R-32
Choose R-454B if:
- Your preferred manufacturer (Carrier, Trane, Lennox) uses R-454B
- You want the lowest possible GWP (466 vs 675)
- You're installing a ducted system where manufacturer selection matters more than refrigerant type
In either case, prioritize:
- SEER2 rating appropriate for your climate
- Proper system sizing (Manual J load calculation)
- Quality installation by an A2L-trained contractor
- Strong warranty terms
- Compatibility with your existing ductwork and electrical infrastructure
The Future: What Comes After R-32 and R-454B
The refrigerant transition isn't finished. Here's what the industry is watching:
Further GWP reductions: The Kigali Amendment's long-term targets may eventually require GWPs below 150 for residential HVAC. This would push the market toward R-290 (GWP 3), CO2 systems, or next-generation HFO blends.
R-290 expansion: As UL standards evolve and charge limits potentially increase, propane-based split systems could enter the U.S. market. Europe is already moving in this direction.
Solid-state cooling: Technologies like magnetocaloric, electrocaloric, and thermoelastic cooling are in various stages of R&D. These eliminate refrigerants entirely by using solid materials that change temperature under magnetic fields, electric fields, or mechanical stress. Commercial viability is likely 10-20 years away for residential applications.
Updated GWP metrics: The IPCC AR6 revised several GWP values. R-32's AR6 GWP is 771 (up from 675 in AR5). Future regulations may reference AR6, potentially affecting which refrigerants meet threshold requirements. However, current EPA rules use AR5 values.
Key Takeaways
- Know your refrigerant. Check your outdoor unit's data plate — it tells you exactly what's inside.
- R-22 owners: replace now. The combination of sky-high refrigerant costs ($50-100+/lb), system age (16+ years), and low efficiency makes replacement a clear financial win.
- R-410A owners: plan ahead. Your system is fine for now, but budget for rising refrigerant costs and plan replacement around age 12-15.
- R-32 is the new global standard with the best combination of efficiency, environmental impact, and simplicity. R-454B is a strong alternative chosen by several major U.S. brands.
- A2L (mildly flammable) is safe with proper installation. Over 200 million R-32 units operate worldwide with no refrigerant-caused fire incidents. Built-in safety systems provide multiple layers of protection.
- The refrigerant matters less than the installation. Whether R-32 or R-454B, system performance depends far more on proper sizing, quality installation, and regular maintenance than on which specific low-GWP refrigerant is inside.
- R-290 (propane) is emerging for small self-contained units like window ACs but won't replace R-32/R-454B in ducted and split systems anytime soon in the U.S.