HVAC PT Charts
RefrigerantASHRAE R-32

R32 PT Chart

R-32

A2LMildly flammableHFC (pure) AIM Act phase-down
R-32 AHRI Guideline N service cylinderIllustrated 25-pound DOT service cylinder for R-32 in the current AHRI Guideline N standard paint (RAL 7044 light gray-green, industry-uniform since 2020). ASHRAE 34 safety class A2L — red flammability band on the shoulder per AHRI Guideline N. Label panel shows designation R32, safety class A2L, and 100-year GWP 675.R32A2LGWP 67525 LB · NET WT
R-32 ships in the uniform AHRI Guideline N cylinder color (light gray-green, RAL 7044) required industry-wide since 2020. ASHRAE 34 class A2L — red flammability band per AHRI Guideline N[Air-Conditioning, Heating, and Refrigeration Institute (AHRI) 2017].
CH2F2

Pure HFC difluoromethane — the single-component A2L refrigerant replacing R-410A in new residential AC equipment from January 2025 onward under the EPA AIM Act.

Saturation @ 70°F
205.8PSIG
GWP (IPCC AR5)
675100-yr
Temperature glide
≈0°F
Boiling point
-61.0°F
Sourced facts
ASHRAE safety class
A2L[src]
Chemical formula
CH₂F₂[src]
GWP (100-yr)
675IPCC AR5[src]
GWP (AR6)
771IPCC AR6[src]
ODP
0[src]
Normal boiling point
−61.0°F (−51.7°C)[src]
Critical temperature
172.6°F (78.1°C)[src]
Required lubricant
POE[src]
R-32 PT calculator Operating pressures Superheat
A2L
Mildly flammable

Lower toxicity. Flame propagates in air at 60°C, but with a low burning velocity (≤ 10 cm/s) and a heat of combustion < 19,000 kJ/kg. Requires A2L-rated equipment, leak detection, and charge limits per UL 60335-2-40 and ASHRAE 15. R-32, R-454B, R-1234yf, R-1234ze(E), R-452B, R-454C, R-455A, R-516A are A2L.

Flammability
Low (burning velocity ≤ 10 cm/s)
Toxicity
Lower (OEL ≥ 400 ppm)

Classification per ANSI/ASHRAE Standard 34-2022. See full reference.

01

Saturation pressure-temperature curve

Pressure
Temperature
°F
70°F: 205.8 PSIG
Quick lookup — R-32
205.8PSIG(1,419 kPa)
Range: -40 to 150°FOpen full PT calculator →
Common service temperatures
32°F
103PSIG
Freezing
45°F
133PSIG
Heat-pump heat
70°F
206PSIG
Standard
75°F
223PSIG
Test ref
80°F
241PSIG
Warm
95°F
303PSIG
Summer peak

Saturation values from CoolProp 7.2.0 R32. Operating pressure on a running system differs — see what R-32 operating pressures should be.

02

R-32 PT chart PDF — printable saturation table

Looking for the R-32 PT chart PDF for shop reference? The complete pressure-temperature saturation table is below — every 1° increment from −40°F to 150°F (or to the refrigerant's critical temperature). Use the Print / Save as PDF button in the table header to download a clean, table-only PDF (the rest of the page is hidden from the print output). Important service temperatures (normal boiling point, freezing point of water, residential AC evap and condenser targets) are tinted and tagged in the table for at-a-glance shop reference.

R-32 PT Chart — Pressure-Temperature Saturation Table

1° increments · Source: CoolProp 7.2.0 / manufacturer datasheet · hvacptcharts.com

R-32 · 1° increments · °F / PSIG
Tinted rows: 32°F H₂O freeze · 40°F AC evap target · 70°F Room T · 95°F AHRI design ambient · 110°F Typical cond saturation
R-32 pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)Pressure (PSIG)
-40°F11.0
-39°F11.7
-38°F12.4
-37°F13.0
-36°F13.7
-35°F14.4
-34°F15.2
-33°F15.9
-32°F16.6
-31°F17.4
-30°F18.2
-29°F19.0
-28°F19.8
-27°F20.6
-26°F21.4
-25°F22.3
-24°F23.2
-23°F24.1
-22°F25.0
-21°F25.9
-20°F26.8
-19°F27.8
-18°F28.7
-17°F29.7
-16°F30.7
-15°F31.7
-14°F32.8
-13°F33.8
-12°F34.9
-11°F36.0
-10°F37.1
-9°F38.2
-8°F39.4
-7°F40.5
-6°F41.7
-5°F42.9
-4°F44.1
-3°F45.4
-2°F46.7
-1°F48.0
0°F49.3
1°F50.6
2°F51.9
3°F53.3
4°F54.7
5°F56.1
6°F57.5
7°F59.0
8°F60.5
9°F62.0
10°F63.5
11°F65.0
12°F66.6
13°F68.2
14°F69.8
15°F71.5
16°F73.1
17°F74.8
18°F76.5
19°F78.3
20°F80.0
21°F81.8
22°F83.6
23°F85.5
24°F87.3
25°F89.2
26°F91.1
27°F93.1
28°F95.1
29°F97.1
30°F99.1
31°F101.2
32°FH₂O freeze103.2
33°F105.3
34°F107.5
35°F109.7
36°F111.9
37°F114.1
38°F116.3
39°F118.6
40°FAC evap target121.0
41°F123.3
42°F125.7
43°F128.1
44°F130.5
45°F133.0
46°F135.5
47°F138.0
48°F140.6
49°F143.2
50°F145.8
51°F148.5
52°F151.2
53°F153.9
54°F156.7
55°F159.5
56°F162.3
57°F165.2
58°F168.1
59°F171.1
60°F174.1
61°F177.1
62°F180.1
63°F183.2
64°F186.3
65°F189.5
66°F192.7
67°F195.9
68°F199.2
69°F202.5
70°FRoom T205.8
71°F209.2
72°F212.6
73°F216.1
74°F219.6
75°F223.2
76°F226.7
77°F230.4
78°F234.0
79°F237.7
80°F241.5
81°F245.3
82°F249.1
83°F253.0
84°F256.9
85°F260.9
86°F264.9
87°F268.9
88°F273.0
89°F277.1
90°F281.3
91°F285.6
92°F289.8
93°F294.1
94°F298.5
95°FAHRI design ambient302.9
96°F307.4
97°F311.9
98°F316.4
99°F321.0
100°F325.7
101°F330.4
102°F335.1
103°F339.9
104°F344.8
105°F349.6
106°F354.6
107°F359.6
108°F364.6
109°F369.7
110°FTypical cond saturation374.9
111°F380.1
112°F385.3
113°F390.6
114°F396.0
115°F401.4
116°F406.9
117°F412.4
118°F418.0
119°F423.6
120°F429.3
121°F435.1
122°F440.9
123°F446.8
124°F452.7
125°F458.7
126°F464.7
127°F470.8
128°F477.0
129°F483.2
130°F489.5
131°F495.8
132°F502.2
133°F508.7
134°F515.2
135°F521.8
136°F528.5
137°F535.2
138°F542.0
139°F548.9
140°F555.8
141°F562.8
142°F569.8
143°F577.0
144°F584.1
145°F591.4
146°F598.7
147°F606.1
148°F613.6
149°F621.2
150°F628.8
CoolProp 7.2.0 · PSIG/kPa = gauge · PSIA = PSIG + 14.696 · kPa(abs) = kPa(gauge) + 101.325

Full saturation values at 1° increments — toggle between °F / PSIG and °C / kPa. Use Print / Save as PDF for laminated shop reference, or download the CSV / JSON below for use in other tools. R-32 PT chart data: CoolProp 7.2.0 (REFPROP-compatible Helmholtz EOS) or manufacturer datasheet, validated against AHRI Standard 700-2019.

03

At a glance

Chemistry

CH2F2
Difluoromethane

Lubricant compatibility

POEMOAB

POE required. A2L mild flammability: low burning velocity, but requires A2L-rated equipment, leak detection, and ventilation per UL 60335-2-40 / ASHRAE 15.

Trade names

  • Forane 32Arkema
  • Genetron 32Honeywell

Common applications

  • Residential central air conditioning (replacing R-410A in new equipment)
  • Heat pumps (residential and light commercial)
  • VRF/VRV systems
  • Light commercial split systems
04

Properties

  • Boiling point (1 atm)
    -51.6°C / -61.0°F
  • Critical point
    172.6°F at 824 PSIG
  • Molar mass
    52.02 g/mol
  • Temperature glide
    Negligible (0.00°F)
  • ODP
    0
  • GWP (AR5, 100-yr)
    675
  • GWP (AR6, 100-yr)
    771
  • Atmospheric lifetime
    5.2 years
05

What is R-32?

R-32 is pure difluoromethane (CH₂F₂), a single-molecule HFC with no temperature glide and no chlorine [ashrae34]. It is also one of the two components of R-410A (50% by mass) — pure R-32 has been adopted as the new-equipment replacement for R-410A in many residential AC markets.

The defining trade-off vs R-410A is the safety class change from A1 (non-flammable) to A2L (mildly flammable, low burning velocity). A2L requires equipment-level safety design — sealed motors, charge limits per ASHRAE 15, and refrigerant leak detection where applicable [ul60335].

Where R-32 is used

  • Residential central AC — new equipment 2025+ (Daikin, Mitsubishi, LG, Fujitsu lead)
  • Residential heat pumps — increasingly the choice over R-454B for some OEMs
  • Light commercial split systems and ductless mini-splits
  • VRF / VRV multi-zone systems
  • Component of the R-410A blend (50% mass) and many other HFC/HFO blends

Regulatory & phase-down status

R-32 itself is not subject to active phase-down. Its GWP of 675 sits just below the EPA AIM Act 700-GWP threshold for new residential AC equipment [aimact]. R-32 is one of the two industry-standard replacements for R-410A (alongside R-454B, GWP 466).

Long-term, the EU F-Gas Regulation revision (2024) targets even lower GWP thresholds in some segments, which may eventually pressure R-32. For 2025-2035, R-32 has stable regulatory positioning in the US residential AC market.

Service notes

POE oil is required (same lubricant family as R-410A) — mineral oil and alkylbenzene are not miscible. ISO 32 viscosity is typical for residential split systems [ahri700].

A2L safety class requires specific procedures: no open flames during service (nitrogen purge for brazing — standard practice for any HFC), A2L-rated leak detection sensors, charge limits per UL 60335-2-40 and ASHRAE 15 [ul60335][ashrae15]. R-32 operating pressures are approximately 5-8% above R-410A; R-410A-rated service equipment (800 PSI manifold) handles R-32 without modification.

07

Operating cycle

CompressorRaises pressureCondenserRejects heat to outdoorsExpansion deviceDrops pressureEvaporatorAbsorbs heat from indoorsDischarge: 375 PSIG, 180°FLiquid: 375 PSIG, 100°FEvap inlet: 121 PSIG, 40°F (two-phase)Suction: 121 PSIG, 50°FTypical residential cooling cycle for R-32 (40°F evap, 110°F condenser, 10°F superheat, 10°F subcooling)
08

Phase-down timeline

No phase-down milestones documented for R-32 in this build. This may mean: (a) no regulatory phase-down currently published; (b) the refrigerant has local regulatory schedules not yet transcribed into the site dataset; or (c) it is a specialty refrigerant outside the main regulatory frameworks. For authoritative current status, consult the EPA AIM Act allocations (40 CFR Part 84), EU F-Gas Regulation 517/2014 + 2024/573, and the relevant national implementations of the Kigali Amendment.

Properties: GWP (AR5) 675 · ODP 0 · AIM Act affected · type: hfc-pure
09

Global warming potential, in context

Residential air conditioning

R-454B466R-32675R-452B698R-407C1.8kR-221.8kR-410A2.1kEU F-Gas (150)EPA AIM Act (700)
10

Retrofit and replacement paths

R-32 replaces

Reading the R-32 pressure-temperature chart

R-32's PT chart is a single curve because R-32 is a pure single-component refrigerant — no blend means no temperature glide and no bubble/dew distinction [ashrae34]. The curve plots saturation pressure on the vertical axis against temperature on the horizontal axis; the line is the phase boundary at thermodynamic equilibrium.

For service measurement, this single-curve simplicity matters: superheat = suction line temp − saturation temp at suction pressure, and subcooling = saturation temp at discharge pressure − liquid line temp, with no glide correction needed. R-32 is operationally as simple as R-22 was — pure-refrigerant behavior with the high-capacity advantage of modern HFCs.

Why this matters for the R-410A transition

Pure-component simplicity gives R-32 a service-procedure advantage over R-410A. R-410A is technically a blend (50/50 R-32/R-125), though the near-azeotropic composition reduces the practical impact. R-32 has zero glide by chemistry — no measurement correction needed across any operating range.

Why R-32 operates 5-8% higher than R-410A

R-32 is the lighter and more volatile component of the R-410A 50/50 blend. Pure R-32 has lower molar mass (52.02 g/mol versus R-410A's blend average of ~72.6 g/mol) and a slightly lower normal boiling point (−61°F versus R-410A's effective −60.6°F). The smaller molecule produces higher vapor pressure at any given temperature.

At a 70°F bench-test condition, R-32 saturation is approximately 206 PSIG versus R-410A's 202 PSIG (CoolProp 7.2.0). At 95°F outdoor design ambient, R-32 saturation is approximately 296 PSIG versus R-410A's 278 PSIG. The 5-8% delta is consistent across the residential operating envelope.

The pressure delta is small enough that R-410A-rated service equipment (800 PSI manifold gauges, hoses, recovery) handles R-32 without modification. R-32 was deliberately engineered to share the R-410A service tool ecosystem — the operational transition for service technicians from R-410A to R-32 is far simpler than the R-22 to R-410A transition was [accamanualT].

R-32's chemistry — pure difluoromethane is the simplest fluorinated refrigerant

R-32 is difluoromethane: a single carbon atom bonded to two hydrogen atoms and two fluorine atoms (CH₂F₂). It's the simplest fluorocarbon used as a commercial refrigerant — smaller than R-22 (CHClF₂) by one atom (no chlorine) and smaller than R-134a (CH₂FCF₃) by an entire carbon-fluorine unit.

The small molecule has thermodynamic advantages. Volumetric refrigerating capacity is approximately 10-15% higher than R-410A in equivalent compressor displacement — meaning an R-32 system can deliver the same cooling with a smaller compressor or the same compressor with about 10% less refrigerant charge [daikin]. Heat transfer coefficients are higher in evaporator and condenser tube banks, improving heat exchanger efficiency.

The disadvantages are flammability and discharge temperature. The two C-H bonds in R-32 give it enough fuel value to support flame propagation in air at certain concentrations — slowly enough to classify as A2L (burning velocity ≤10 cm/s) rather than the higher A2 or A3 flammable classes, but still requires equipment-level safety design [ul60335]. Discharge temperature from the compressor is approximately 30-40°F higher than R-410A at equivalent operating conditions; compressor designs account for this with different motor cooling and oil-management approaches.

ODP 0 and GWP 675 — why R-32 clears the AIM Act threshold

R-32 has zero ozone-depletion potential because the molecule contains no chlorine [ashrae34]. The Montreal Protocol HCFC phase-down that eliminated R-22 does not apply to R-32 — it's a hydrofluorocarbon (HFC), classified separately, and not on the Montreal Protocol controlled substances list.

R-32's GWP of 675 (IPCC AR5, 100-year horizon) places it just below the EPA AIM Act regulatory threshold of 700-GWP for new residential AC equipment manufactured on or after 1 January 2025 [aimact]. The 700-GWP threshold was set deliberately to allow R-32 (and the slightly lower R-454B at 466) while excluding R-410A (2088), R-404A (3922), and most other legacy HFC blends.

The 675 GWP figure is not a coincidence

The 700-GWP threshold was selected during the AIM Act technology transitions rulemaking to enable the residential AC industry's transition to A2L refrigerants. R-32 at 675 fits; R-454B at 466 fits more comfortably; pure HFOs and natural refrigerants fit by orders of magnitude. R-410A at 2088 doesn't.

AR5 (675) vs AR6 (771) — why the regulatory number stays at 675

The two figures come from sequential IPCC assessment reports. AR5 (Fifth Assessment Report, 2014) computed R-32's 100-year GWP as 675 using the atmospheric chemistry and radiative-forcing models available at that time [ipccar5]. AR6 (Sixth Assessment Report, 2021) updated those models and produced 771 — a ~14% upward revision driven by improved understanding of indirect effects and atmospheric chemistry feedbacks [ipccar6].

The EPA AIM Act uses AR5 values for regulatory determinations, not AR6. This keeps policy values stable — re-baselining regulatory thresholds against every new IPCC report would create implementation chaos. So when comparing R-32 to the 700-GWP threshold, use the AR5 figure of 675.

For scientific communication and international reporting under the Paris Agreement, AR6 figures are increasingly preferred. The two values represent the same underlying atmospheric chemistry — just better-modeled in AR6. Either is defensible; the right choice depends on whether you're working a regulatory question (AR5) or a scientific one (AR6).

Critical point and molar mass — implications for chiller and cascade use

R-32's critical temperature is 78.1°C (172.6°F) and critical pressure is approximately 824 PSIA (810 PSIG) [coolprop]. The critical temperature is significantly lower than R-410A's effective ~158°F or R-22's 205°F — meaning R-32's usable saturation range tops out earlier on the high side.

In residential and light commercial AC operation, the critical point is comfortably above any realistic condenser temperature (95°F design ambient gives saturation around 110-130°F at the condenser outlet, well below 172°F critical). For high-temperature applications — industrial heat pumps, process cooling above 130°F ambient — R-32 reaches its critical region and transitions toward supercritical behavior. R-32 is therefore well-suited to standard AC but not the heat-pump and cascade applications where R-410A or R-134a have more headroom.

The molar mass of 52.02 g/mol makes R-32 one of the lighter refrigerants in current commercial use. Light molecules have lower mass per cycle through the compressor for equivalent volumetric flow — partially offset by R-32's higher volumetric capacity, but the net effect is smaller refrigerant charge for the same cooling capacity. A typical residential R-32 system uses roughly 10-15% less refrigerant by mass than the equivalent R-410A system, which combines with R-32's lower GWP to substantially reduce total CO₂-equivalent climate impact per installation.

Reading the common service temperatures for R-32

The quick-lookup pills above the PT chart show R-32 saturation pressures at six service-relevant temperatures. Compared to R-410A at the same temperatures, R-32 values run 5-8% higher across the operating range.

  • 32°F (freezing) — R-32 saturation approximately 110 PSIG; iced-up evaporator territory.
  • 45°F (heat-pump heating) — typical winter outdoor coil temperature when heat pump is heating; R-32 saturation around 145 PSIG.
  • 70°F (standard reference) — R-32 saturation 206 PSIG; bench reference.
  • 75°F (test reference) — typical indoor return-air conditions.
  • 80°F (warm-weather operation) — R-32 saturation approximately 235 PSIG.
  • 95°F (summer peak) — AHRI 210/240 test condition; R-32 saturation approximately 296 PSIG.

For comparison, R-22 at 95°F is 181 PSIG and R-410A is 278 PSIG — R-32 sits about 5% above R-410A and 65% above R-22. The R-32 to R-410A delta is small enough that R-410A-trained technicians need minimal pressure-envelope retraining for R-32 work.

A2L equipment requirements — what changes from R-410A

R-32's A2L safety class requires equipment-level accommodations that R-410A's A1 did not. The pressure envelope is essentially identical to R-410A (within 5-8%), so service-equipment pressure ratings (800 PSI manifold gauges, hoses, recovery cylinders) carry over from R-410A practice. What changes is everything related to potential ignition sources.

| Equipment / procedure | R-410A (A1) | R-32 (A2L) | | --- | --- | --- | | Manifold gauge rating | 800 PSI | 800 PSI | | Recovery cylinder | Pink, 600 PSI service | Yellow with red top stripe (A2L marker), 600 PSI | | Compressor motor | Standard hermetic | Sealed motor in refrigerant circuit per UL 60335-2-40 | | Charge limits | None (A1) | Scaled to smallest enclosed space per ASHRAE 15 | | Leak detection | Optional | Required in some installations per UL 60335-2-40 | | Brazing during service | Nitrogen purge standard | Nitrogen purge mandatory; no open flames near system | | Lubricant | POE | POE (same family) | | Vacuum target | 500 microns held 30+ min | 500 microns held 30+ min |

The transition from R-410A-only service to R-32-capable service is primarily about A2L procedures and equipment certifications, not pressure-envelope retraining. Service technicians moving from R-410A to R-32 typically complete a 1-2 day A2L familiarization course offered by major distributors and OEMs.

POE lubricant — same chemistry as R-410A

R-32 requires polyolester (POE) oil, the same lubricant family used with R-410A and most other HFC refrigerants [ahri700]. Typical residential R-32 systems use ISO 32 viscosity POE; commercial applications may use ISO 22 or ISO 46. The viscosity grade is specified by the equipment OEM and reflects the compressor design — verify against equipment service literature before adding oil to a system.

POE's compatibility with R-32 derives from its polar ester groups, which mix with the polar HFC molecule and return reliably through the compressor in the refrigerant flow. This is fundamentally different from R-22's mineral oil, which is non-polar and would not mix with R-32. Mixing oils across the HCFC/HFC boundary causes immediate lubrication failure — never use mineral oil residue from an R-22 system in R-32 service.

POE oil is hygroscopic: it absorbs atmospheric moisture rapidly when exposed to air. Moisture in a sealed refrigeration system reacts with POE to form weak organic acids that corrode metal surfaces and degrade lubrication performance over time. The defense is rigorous vacuum: 500 microns held for at least 30 minutes before opening the system to refrigerant. A failing vacuum hold indicates a leak or residual moisture that must be resolved before charging.

The Daikin lead and the global R-32 transition timeline

R-32 was commercialized for residential AC by Daikin Industries in Japan in 2012 [daikin]. Daikin held patents covering several aspects of R-32 system design and application — compressor lubrication, oil return management, A2L safety circuit design — that gave the company a significant lead time over competitors as the residential AC industry transitioned away from R-410A.

The global R-32 deployment timeline:

  • 2012-2013 — Daikin commercial launch in Japan
  • 2014-2016 — Mitsubishi Electric and LG follow in Asia; EU market entry begins
  • 2017-2019 — EU deployment expands ahead of EU F-Gas threshold tightening
  • 2018-2020 — US market entry; Daikin and Mitsubishi residential equipment available
  • 2024 — Carrier, Trane, Lennox announce R-454B (not R-32) for their US residential lines
  • 1 January 2025 — EPA AIM Act technology transitions rule effective; R-410A no longer permitted in new residential AC

US Carrier, Trane, and Lennox standardized on R-454B (R-32/R-1234yf 68.9/31.1, GWP 466) rather than pure R-32 — the choice was driven by patent licensing considerations and OEM strategy rather than R-32 technical limitations. The two paths (R-32 or R-454B) coexist in the US market; both clear the AIM Act 700-GWP threshold, both are A2L, both use POE oil.

How to think about R-32 in 2026 and beyond

R-32 is one of the two dominant new-equipment residential AC refrigerants in 2026, alongside R-454B. The choice between them is driven primarily by equipment availability in your market — Daikin / Mitsubishi / LG / Fujitsu lines use R-32; Carrier / Trane / Lennox lines use R-454B. Performance is comparable; service procedures are A2L for both.

R-32's regulatory positioning is stable through 2035 at minimum. GWP 675 sits below the AIM Act 700 threshold; the AIM Act production schedule reaches 85% reduction by 2036 but R-32 (being a low-GWP HFC) consumes less production allocation per kg than higher-GWP refrigerants. EU F-Gas Regulation revisions (2024) target tighter thresholds in some segments — small split AC may face sub-150-GWP requirements by 2030, which would push beyond R-32 toward pure HFO blends or natural refrigerants. The US is not on that trajectory in 2026.

For technicians, R-32 work resembles R-410A work with A2L procedures added on top: same pressures (within 5-8%), same lubricant family (POE), same vacuum discipline, same gauge ratings, same charging-by-weight approach. The A2L safety procedures (no open flames near refrigerant, A2L-rated leak detection, charge limits) are the meaningful operational difference from R-410A practice.

11

Frequently asked

›What is the normal operating pressure of R-32?

Very similar to R-410A — about 5-8% higher across the operating envelope. At 95°F outdoor, expect roughly 140 PSIG suction and 380 PSIG discharge on a properly-charged residential R-32 system. R-32 saturation at 95°F is approximately 296 PSIG (CoolProp 7.2.0).

›Is R-32 flammable?

Yes — R-32 is ASHRAE class A2L, mildly flammable with low burning velocity (≤10 cm/s) and limited heat of combustion [ashrae34]. The classification reflects flammability conditions that require sustained ignition source and specific concentration in air to propagate flame.

Equipment design accommodates the flammability per UL 60335-2-40: sealed motors in the refrigerant circuit, A2L-rated leak detection in some installations, and charge limits scaled to the smallest enclosed space the system serves [ul60335]. Treating R-32 as if it were A1 R-410A is a safety-critical error.

›What is R-32's GWP?

675 per IPCC AR5 (the EPA AIM Act regulatory figure). The IPCC AR6 value (2021) is approximately 771, reflecting updated atmospheric chemistry models — but US regulation continues to use the AR5 figure [aimact][ipccar5].

The AIM Act threshold for residential AC equipment is 700 GWP, placing R-32 just inside the permitted range — a deliberate result of the residential A2L transition.

›Why is R-32 replacing R-410A?

Two reasons. (1) GWP: R-32 at 675 falls below the AIM Act 700 threshold for new residential AC; R-410A at 2088 does not [aimact]. (2) Capacity: R-32 has approximately 10-15% higher volumetric refrigerating capacity than R-410A, allowing smaller charge for equivalent cooling output.

R-454B (GWP 466, R-32/R-1234yf blend) is the parallel A2L choice — Daikin / Mitsubishi / LG / Fujitsu favor pure R-32; Carrier / Trane / Lennox favor R-454B.

›What gauges and recovery equipment do I need for R-32?

R-410A-rated 800 PSI manifolds work for R-32 from a pressure-rating standpoint. Recovery cylinders are color-coded yellow with a red top stripe for A2L refrigerants (distinct from R-410A's pink cylinder).

A2L-specific recovery machines exist; R-410A recovery machines can be used for A2L only if specifically certified by the manufacturer — check the equipment marking. Hoses must be rated for working pressure and resistant to refrigerant permeation.

›What lubricant does R-32 use?

Polyolester (POE) oil — the same lubricant family used with R-410A [ahri700]. Typical viscosity is ISO 32 for residential split systems; commercial applications may use ISO 22 or ISO 46.

POE is hygroscopic — absorbs moisture aggressively from atmospheric humidity. Vacuum to 500 microns and hold ≥30 minutes before charging.

›Can I retrofit an R-410A system to R-32?

No, not safely. R-410A equipment is A1-rated (no flammability accommodations); R-32 is A2L and requires sealed motors and A2L-rated safety design per UL 60335-2-40. Retrofitting an A1-rated chassis to an A2L refrigerant is not permitted by most equipment OEMs and is non-compliant with code in most jurisdictions [ul60335].

For an R-410A system needing major work, the path is full replacement with new R-32 or R-454B equipment.

›Why did Daikin lead the R-32 transition?

Daikin Industries commercialized R-32 in residential AC starting in Japan in 2012 and then globally — they hold extensive patents on the R-32 application know-how [daikin]. Their R-32 deployment ramped through Asia and Europe years before the US AIM Act made it the dominant new-equipment choice.

US Daikin / Mitsubishi / LG / Fujitsu carried that experience forward when AIM Act timing forced industry-wide R-410A transition in 2025. Carrier / Trane / Lennox standardized on R-454B as an alternative path.

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Full PT chart for R-32 · CC BY 4.0 · attribute the source

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Sources & citations

  1. [1]
    ASHRAE Standard 34-2022 — Designation and Safety Classification of Refrigerants
    2022https://www.ashrae.org/technical-resources/standards-and-guidelines
  2. [2]
    IPCC AR5 (2014) Working Group I, Chapter 8, Table 8.A.1
    2014https://www.ipcc.ch/report/ar5/wg1/
  3. [3]
    IPCC AR6 (2021) Working Group I, Chapter 7, Annex IIIA
    2021https://www.ipcc.ch/report/ar6/wg1/
  4. [4]
    EPA AIM Act — 40 CFR Part 84 Subpart B (HFC Phase-down) + Technology Transitions Rule
    Final Rule Oct 2021, Technology Transitions Rule Oct 2023https://www.epa.gov/climate-hfcs-reduction
  5. [5]
    EPA Significant New Alternatives Policy (SNAP) — Acceptable substitutes for residential AC
    https://www.epa.gov/snap
  6. [6]
    UL 60335-2-40 / IEC 60335-2-40 — Safety requirements for AC equipment using A2L refrigerants
    https://www.ul.com/services/ul-60335-standards
  7. [7]
    ASHRAE Standard 15-2022 — Safety Standard for Refrigeration Systems (A2L charge limits)
    2022https://www.ashrae.org/technical-resources/standards-and-guidelines
  8. [8]
    CoolProp 7.2.0 (Bell, Wronski, Quoilin, Lemort 2014) — REFPROP-compatible Helmholtz EOS
    2014 (continually updated)http://www.coolprop.org/doi:10.1021/ie4033999
  9. [9]
    AHRI Standard 700-2019 — Specifications for Refrigerants
    2019https://www.ahrinet.org/search-standards
  10. [10]
    Daikin Industries — R-32 commercial deployment documentation
    Commercial launch 2012 (Japan), US 2018+https://www.daikin.com/products/ac/r32/
  11. [11]
    NIST Chemistry WebBook — Difluoromethane thermophysical properties (CAS 75-10-5)
    https://webbook.nist.gov/chemistry/fluid/

Data sources & provenance

PT chart
CoolProp 7.2.0 R32
Cross-checked against
CoolProp 7.2.0 (R32); Arkema Forane 32 datasheet; ASHRAE Handbook of Refrigeration 2022
Properties
CoolProp 7.2.0 + ASHRAE Standard 34-2022
GWP
IPCC AR5 Table 8.A.1
Generated
2026-07-14

Reference material. Always verify pressure values against the equipment data plate and manufacturer service literature before charging or troubleshooting a specific system. Saturation pressure differs from operating pressure — see superheat & subcooling fundamentals.