HVAC PT ChartsVerified saturation data · 61 refrigerants
RefrigerantASHRAE R-134a

R-134a

A1Non-flammableHFC (pure) AIM Act phase-down
CH2FCF3

Pure HFC tetrafluoroethane — the workhorse mobile-AC and centrifugal-chiller refrigerant from the early 1990s; being replaced by R-1234yf in mobile AC and by R-513A / R-450A in chillers.

Saturation @ 70°F
71.1PSIG
GWP (IPCC AR5)
1430100-yr
Temperature glide
≈0°F
Boiling point
-14.9°F
Sourced facts
ASHRAE safety class
A1[src]
Chemical formula
CH₂FCF₃[src]
GWP (100-yr)
1430IPCC AR5[src]
GWP (AR6)
1530IPCC AR6[src]
ODP
0[src]
Normal boiling point
−14.9°F (−26.1°C)[src]
Critical temperature
213.9°F (101.1°C)[src]
Required lubricant
POE / PAG[src]
R-134a PT calculator Operating pressures Superheat
A1
Non-flammable

Lower toxicity (Occupational Exposure Limit ≥ 400 ppm). No flame propagation in air at standard atmospheric pressure and 60°C. R-134a, R-22, R-410A, R-404A, R-744 (CO2) are A1.

Flammability
None (no flame propagation)
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: 71.1 PSIG
Quick lookup — R-134a
71.1PSIG(490 kPa)
Range: -40 to 150°FOpen full PT calculator →
Common service temperatures
32°F
28PSIG
Freezing
45°F
40PSIG
Heat-pump heat
70°F
71PSIG
Standard
75°F
79PSIG
Test ref
80°F
87PSIG
Warm
95°F
114PSIG
Summer peak

Saturation values from CoolProp 7.2.0 R134a. Operating pressure on a running system differs — see what R-134a operating pressures should be.

02

R-134a PT chart PDF — printable saturation table

Looking for the R-134a 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-134a PT Chart — Pressure-Temperature Saturation Table

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

R-134a · 1° increments · °F / PSIG
Tinted rows: NBP atmospheric crossover · 32°F H₂O freeze · 40°F Chiller evap LCHW · 100°F Cond saturation · 130°F High-side limit
R-134a pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)Pressure (PSIG)
-40°F-7.3
-39°F-7.0
-38°F-6.8
-37°F-6.6
-36°F-6.4
-35°F-6.1
-34°F-5.9
-33°F-5.6
-32°F-5.4
-31°F-5.1
-30°F-4.8
-29°F-4.6
-28°F-4.3
-27°F-4.0
-26°F-3.7
-25°F-3.4
-24°F-3.1
-23°F-2.8
-22°F-2.5
-21°F-2.1
-20°F-1.8
-19°F-1.5
-18°F-1.1
-17°F-0.8
-16°F-0.4
-15°F-0.0
-14°FNBP (atmospheric)0.3
-13°F0.7
-12°F1.1
-11°F1.5
-10°F1.9
-9°F2.4
-8°F2.8
-7°F3.2
-6°F3.6
-5°F4.1
-4°F4.6
-3°F5.0
-2°F5.5
-1°F6.0
0°F6.5
1°F7.0
2°F7.5
3°F8.0
4°F8.5
5°F9.1
6°F9.6
7°F10.2
8°F10.8
9°F11.3
10°F11.9
11°F12.5
12°F13.1
13°F13.8
14°F14.4
15°F15.0
16°F15.7
17°F16.4
18°F17.0
19°F17.7
20°F18.4
21°F19.1
22°F19.9
23°F20.6
24°F21.4
25°F22.1
26°F22.9
27°F23.7
28°F24.5
29°F25.3
30°F26.1
31°F26.9
32°FH₂O freeze27.8
33°F28.6
34°F29.5
35°F30.4
36°F31.3
37°F32.2
38°F33.1
39°F34.1
40°FChiller evap LCHW35.0
41°F36.0
42°F37.0
43°F38.0
44°F39.0
45°F40.0
46°F41.1
47°F42.2
48°F43.2
49°F44.3
50°F45.4
51°F46.6
52°F47.7
53°F48.9
54°F50.0
55°F51.2
56°F52.4
57°F53.6
58°F54.9
59°F56.1
60°F57.4
61°F58.7
62°F60.0
63°F61.3
64°F62.7
65°F64.0
66°F65.4
67°F66.8
68°F68.2
69°F69.7
70°F71.1
71°F72.6
72°F74.1
73°F75.6
74°F77.1
75°F78.7
76°F80.2
77°F81.8
78°F83.4
79°F85.0
80°F86.7
81°F88.4
82°F90.0
83°F91.8
84°F93.5
85°F95.2
86°F97.0
87°F98.8
88°F100.6
89°F102.5
90°F104.3
91°F106.2
92°F108.1
93°F110.0
94°F112.0
95°F114.0
96°F115.9
97°F118.0
98°F120.0
99°F122.1
100°FCond saturation124.2
101°F126.3
102°F128.4
103°F130.6
104°F132.8
105°F135.0
106°F137.2
107°F139.4
108°F141.7
109°F144.0
110°F146.4
111°F148.7
112°F151.1
113°F153.5
114°F156.0
115°F158.4
116°F160.9
117°F163.4
118°F166.0
119°F168.6
120°F171.2
121°F173.8
122°F176.4
123°F179.1
124°F181.8
125°F184.6
126°F187.3
127°F190.2
128°F193.0
129°F195.8
130°FHigh-side limit198.7
131°F201.6
132°F204.6
133°F207.6
134°F210.6
135°F213.6
136°F216.7
137°F219.8
138°F222.9
139°F226.0
140°F229.2
141°F232.4
142°F235.7
143°F239.0
144°F242.3
145°F245.7
146°F249.0
147°F252.5
148°F255.9
149°F259.4
150°F262.9
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-134a 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

CH2FCF3
1,1,1,2-Tetrafluoroethane

Lubricant compatibility

POEPAGMOAB

Mobile AC originally used R-134a with PAG oil; stationary equipment uses POE. POE is hygroscopic — pull deep vacuum before charging.

Trade names

  • Suva 134aChemours (historical: DuPont)
  • Genetron 134aHoneywell
  • Forane 134aArkema

Common applications

  • Mobile air conditioning (legacy vehicles pre-2014)
  • Medium-temperature commercial refrigeration
  • Centrifugal chillers (medium-pressure)
  • Domestic refrigerators (legacy)
04

Properties

  • Boiling point (1 atm)
    -26.1°C / -14.9°F
  • Critical point
    213.9°F at 574 PSIG
  • Molar mass
    102.03 g/mol
  • Temperature glide
    Negligible (0.00°F)
  • ODP
    0
  • GWP (AR5, 100-yr)
    1430
  • GWP (AR6, 100-yr)
    1530
  • Atmospheric lifetime
    14 years
05

What is R-134a?

R-134a is pure 1,1,1,2-tetrafluoroethane (CH₂FCF₃), a single-molecule HFC with no temperature glide [ashrae34]. It replaced CFC R-12 in mobile air conditioning, centrifugal chillers, and domestic refrigeration in the early 1990s as the Montreal Protocol phased out CFCs.

R-134a operates at moderate pressures (saturation 71 PSIG at 70°F per CoolProp 7.2.0) and uses POE oil for stationary applications, PAG oil for mobile AC. Its A1 non-flammable safety class made it operationally easy across diverse equipment types.

Where R-134a is used

  • Mobile AC — vehicles built before EU 2017 / US 2021 R-1234yf transitions
  • Centrifugal chillers — water-cooled, large commercial cooling
  • Domestic refrigeration — household refrigerators (legacy)
  • Vending machines, beverage coolers, and commercial display refrigeration
  • Aerosol propellant in some medical and specialty applications

Regulatory & phase-down status

Mobile AC: EU banned R-134a in new vehicle types after 1 January 2017 under Directive 2006/40/EC; new vehicles use R-1234yf [eumac]. US OEMs transitioned to R-1234yf for most new light-duty vehicles by 2021 ahead of AIM Act pressure.

Stationary applications: R-134a's GWP of 1430 places it above the EPA AIM Act 700-GWP threshold for residential AC categories (R-134a isn't widely used in residential AC anyway), with phase-down restrictions affecting some chiller and commercial refrigeration categories from 2025-2030 [aimact]. R-450A, R-513A, R-515B, R-1234ze(E) are the chiller replacement options.

Service notes

Polyolester (POE) oil is standard for stationary HVAC; polyalkylene glycol (PAG) oil is standard for mobile AC due to better oil return in variable-displacement automotive compressors [ahri700][saej639]. The two are not interchangeable — verify lubricant grade against equipment OEM.

R-134a service equipment is widely available and inexpensive (decades of installed base). Manifold gauges rated 500 PSI cover R-134a's operating envelope (low side ~25-40 PSIG, high side ~150-220 PSIG for typical applications). Recovery is mandatory under EPA Section 608.

07

Operating cycle

CompressorRaises pressureCondenserRejects heat to outdoorsExpansion deviceDrops pressureEvaporatorAbsorbs heat from indoorsDischarge: 146 PSIG, 180°FLiquid: 146 PSIG, 100°FEvap inlet: 35 PSIG, 40°F (two-phase)Suction: 35 PSIG, 50°FTypical residential cooling cycle for R-134a (40°F evap, 110°F condenser, 10°F superheat, 10°F subcooling)
08

Phase-down timeline

2021202220232024202520262027202820292030today (2026-06-12)
2021-01-01
EPA SNAP delisting of R-134a in new mobile AC (per 2015 rule, after MVAC industry transition)
2029-01-01
AIM Act phase-down: 70% reduction baseline
Regulatory timeline for R-134a
09

Global warming potential, in context

Medium-pressure centrifugal & screw chillers

R-515B293R-515A392R-450A605R-513A631R-134a1.4kEU F-Gas (150)EPA AIM Act (700)
10

Retrofit and replacement paths

R-134a replaces

Replacements for R-134a

Reading the R-134a pressure-temperature chart

R-134a's PT chart is a single curve because R-134a is a pure single-component refrigerant — no temperature glide and no bubble/dew distinction [ashrae34]. Read across from a measured temperature to find the saturation pressure; read up from a measured manifold pressure to find the saturation temperature.

For service measurement: superheat = suction line temp − saturation temp at suction pressure, and subcooling = saturation temp at discharge pressure − liquid line temp. No glide correction needed across any application. This pure-refrigerant simplicity is one reason R-134a persisted as the dominant mobile AC and centrifugal chiller refrigerant for three decades after the R-12 phase-out.

Why pure refrigerant chemistry matters in service

R-134a's single-component nature means it cannot fractionate during partial charging or leaking. A leaking R-134a system loses refrigerant at the original composition (still pure R-134a); a leaking zeotropic blend like R-407C can lose components at different rates, shifting the remaining charge composition over time and requiring full recovery and recharge rather than topping off.

R-134a's moderate pressure envelope suits chillers and mobile AC

R-134a operates at lower saturation pressures than the HFC blends and pure refrigerants used in residential AC. At 70°F R-134a saturation is 71 PSIG (CoolProp 7.2.0); at 95°F outdoor design ambient, approximately 124 PSIG. Compare to R-410A at 70°F (202 PSIG) and 95°F (278 PSIG) — R-134a runs roughly 55-60% lower across the envelope.

The lower pressure envelope determines R-134a's natural application fit. Centrifugal chillers — large water-cooled units used in commercial buildings — use the moderate pressure for impeller-based compression, where R-134a's pressure ratio and volumetric flow match well with centrifugal compressor design. Mobile AC reciprocating compressors handle R-134a's pressures with conventional valve and seal designs.

For service technicians, R-134a's lower envelope means standard 500 PSI manifold gauges (the pre-R-410A standard) handle R-134a without modification. The R-22 to R-410A pressure-rating step change does not apply to R-134a work — R-22-era service equipment was already adequate. This is why R-134a service has stayed operationally simple across decades of installed equipment.

R-134a chemistry — pure tetrafluoroethane replaces R-12's chlorine

R-134a is 1,1,1,2-tetrafluoroethane: a two-carbon backbone with four fluorine atoms and two hydrogen atoms (CH₂FCF₃). It was specifically engineered in the late 1980s as the HFC replacement for CFC R-12 (dichlorodifluoromethane, CCl₂F₂) — same single-component simplicity, similar moderate pressure envelope, but no chlorine atoms.

The chemistry switch from R-12 to R-134a was driven by Montreal Protocol obligations. R-12 had ODP 1.0 (the reference value for the entire ozone-depletion potential scale); R-134a has ODP 0. The transition began with mobile AC in the early 1990s (Chrysler 1992, Ford 1993, GM 1994) and propagated through chillers, domestic refrigeration, and commercial refrigeration over the following decade.

R-134a's hydrogen atoms make it less stable than fully-saturated CFCs — atmospheric breakdown by OH radicals limits R-134a's lifetime to approximately 14 years, compared to R-12's ~100 years. Shorter atmospheric lifetime translates to lower GWP per kg (R-134a: 1430 vs R-12: 10900), though still well above modern AIM Act and EU F-Gas thresholds.

ODP 0 — the chlorine-elimination success story

R-134a has zero ozone-depletion potential because the molecule contains no chlorine [ashrae34]. The Montreal Protocol CFC phase-out (R-12 banned 1996 in developed countries) was specifically targeting chlorine — atmospheric chemistry research in the 1970s-1980s linked CFC chlorine atoms to stratospheric ozone destruction at catalytic rates.

R-134a's HFC chemistry preserves R-12's refrigeration performance (moderate pressure envelope, single-component simplicity, A1 safety) while eliminating the chlorine. The atmospheric lifetime is also shorter than R-12 because R-134a's hydrogen atoms create breakdown pathways via OH radical reactions in the lower atmosphere — R-134a never reaches the stratosphere in significant quantities.

For practical purposes, R-134a's ODP 0 placed it outside Montreal Protocol restrictions. The follow-on policy framework — the Kigali Amendment (2016) and EPA AIM Act (2020) — added climate-based restrictions (GWP) on top of the existing ozone-based framework. R-134a is restricted under these newer climate-focused rules for some applications, not for ozone reasons.

GWP 1430 (AR5) vs 1530 (AR6) — both above policy thresholds

R-134a's GWP value depends on which IPCC assessment report you reference. AR5 (2014) computed 1430; AR6 (2021) updated to approximately 1530 — a ~7% revision driven by improved atmospheric chemistry modeling [ipccar5][ipccar6]. The EPA AIM Act and EU F-Gas Regulation both use the AR5 value for regulatory determinations.

Both figures place R-134a above the policy thresholds in major segments. EU F-Gas Regulation 517/2014 banned R-134a in new MAC vehicle types from 1 January 2017 under a 150-GWP threshold [eumac]. EPA AIM Act 700-GWP threshold for residential AC doesn't materially affect R-134a (which wasn't used in residential AC anyway), but commercial refrigeration and some chiller categories see R-134a restrictions through 2025-2030 phase-downs.

Two transitions running in parallel

For mobile AC, the regulatory pressure drove industry standardization on R-1234yf (GWP 4) — a single global replacement. For stationary chillers, the regulatory pressure is spread across multiple replacement chemistries with different trade-offs: R-513A and R-450A as A1 retrofits; R-1234ze(E) as A2L new-equipment; R-515B as A1 lower-GWP than R-513A.

Critical point and molar mass — why R-134a works for chillers

R-134a's critical temperature is 101°C (213.9°F) and critical pressure is approximately 588 PSIA (573 PSIG) [coolprop]. The critical temperature is high — well above any normal ambient — so the full saturation curve is usable across all standard HVAC and refrigeration operating ranges. Subcooled liquid forms cleanly in the condenser; superheated vapor leaves the evaporator without supercritical complications.

The molar mass of 102.03 g/mol is heavier than R-22 (86.5 g/mol), R-410A average (~72.6 g/mol), and R-32 (52 g/mol). Heavier molecules have lower volumetric refrigerating capacity per unit compressor displacement — about half the capacity of R-410A in equivalent equipment. This is why R-134a equipment uses larger compressors and condensers than R-410A equipment of equivalent cooling capacity.

For chillers, the lower volumetric capacity is actually an advantage. Centrifugal compressors work most efficiently at moderate pressure ratios and large volumetric flows; R-134a's moderate pressure envelope and large mass-per-volume let centrifugal impellers operate in their optimal aerodynamic regime. R-410A would force centrifugal compressors to operate at unusual pressure ratios for the technology — which is why centrifugal chillers historically used R-134a (or R-123) rather than R-22 or R-410A.

Reading the common service temperatures for R-134a

The quick-lookup pills above the PT chart show R-134a saturation pressures at six service-relevant temperatures. R-134a values are substantially lower than R-22 or R-410A at the same temperatures due to R-134a's heavier molecule and higher boiling point.

  • 32°F (freezing) — R-134a saturation approximately 28 PSIG; refrigerator evaporator territory.
  • 45°F (heat-pump heating) — typical winter outdoor coil temperature; R-134a saturation around 40 PSIG.
  • 70°F (standard reference) — R-134a saturation 71 PSIG; bench reference.
  • 75°F (test reference) — typical indoor return-air conditions; R-134a saturation around 79 PSIG.
  • 80°F (warm-weather operation) — R-134a saturation approximately 87 PSIG.
  • 95°F (summer peak) — AHRI 210/240 test condition; R-134a saturation approximately 124 PSIG.

For mobile AC, the operational range typically runs lower on the suction side (25-45 PSIG when the system is operating in a hot vehicle interior) and higher on the discharge side (180-250 PSIG with engine compartment ambient heating the condenser). For domestic refrigeration the suction side runs near atmospheric (1-5 PSIG at freezer setpoint).

Two lubricant chemistries — POE for stationary, PAG for mobile

R-134a is unique among Tier 1 refrigerants in requiring two different lubricant chemistries depending on application. Stationary HVAC (chillers, commercial refrigeration, vending machines, household refrigerators): polyolester (POE) oil, the same family used with R-410A and R-32 [ahri700]. Mobile AC: polyalkylene glycol (PAG) oil, typically PAG 46 or PAG 100 viscosity grades [saej639].

The reason for the split is automotive compressor design. Mobile AC compressors are mostly variable-displacement (the compressor adjusts its stroke or piston count to match cabin cooling demand), which requires the lubricant to behave predictably across a wider range of operating conditions than stationary HVAC compressors face. PAG oil's specific polymer chemistry provides better oil-return behavior in variable-displacement applications and better seal compatibility with the elastomers used in automotive AC system components.

Never mix POE and PAG in the same R-134a system

POE and PAG are chemically incompatible — mixing them produces oil-return failures, seal degradation, and accelerated compressor wear. If you're working on an R-134a system, verify the lubricant grade against the equipment OEM service literature before adding oil. Mobile AC = PAG (and there are multiple PAG viscosity grades that are not interchangeable); stationary HVAC = POE.

The EU MAC Directive — landmark refrigerant policy

EU Directive 2006/40/EC, commonly called the MAC Directive (Mobile Air Conditioning Directive), was the first major refrigerant regulation to use GWP as the binding compliance threshold [eumac]. The directive required all new vehicle types receiving EU type approval from 1 January 2011 to use refrigerants with GWP below 150, and all new vehicles regardless of type from 1 January 2017.

R-134a's GWP of 1430 placed it well above the 150 threshold. The chosen replacement was R-1234yf (HFO, A2L, GWP 4), which became the dominant new-vehicle MAC refrigerant in the EU from 2011 onward and globally over the following decade. Daimler initially resisted R-1234yf adoption (citing flammability concerns) but ultimately conformed; the broader industry standardized rapidly.

The MAC Directive's significance extended beyond mobile AC. It established the regulatory template for the EU F-Gas Regulation (517/2014, revised 2024) and ultimately influenced the US EPA AIM Act framework — using GWP thresholds tied to specific end-uses rather than blanket refrigerant bans. The 150-GWP threshold remains the EU benchmark for the most aggressive refrigerant categories.

Chiller retrofit paths — R-513A, R-450A, R-515B, R-1234ze(E)

For centrifugal chillers using R-134a, the EU F-Gas and EPA AIM Act phase-down pressure creates four established retrofit / replacement paths:

  • R-513A (R-134a/R-1234yf 56/44, A1, GWP 631) — near-azeotropic blend designed as a true drop-in for R-134a. POE oil; pressure envelope within 5% of R-134a; minimal compressor adjustment needed. Most common R-134a chiller retrofit.
  • R-450A (R-134a/R-1234ze(E) 42/58, A1, GWP 605) — small glide (~0.9°F), POE oil, similar pressure envelope to R-134a. Slightly lower GWP than R-513A.
  • R-515B (R-1234ze(E)/R-227ea 91.1/8.9, A1, GWP 287) — azeotropic blend, lower GWP than R-513A / R-450A. Slightly higher pressures; equipment evaluation needed for retrofit.
  • R-1234ze(E) (pure HFO, A2L, GWP 7) — for new equipment installations; requires A2L-rated chiller design. The long-term low-GWP destination for centrifugal chillers.

The choice among these depends on whether the equipment is being retrofitted (in which case A1 paths preserve safety classification) or replaced (in which case A2L pure HFO offers maximum GWP reduction). New chiller equipment installations from 2024+ increasingly specify R-1234ze(E) for long-term regulatory positioning.

How to think about R-134a in 2026 and beyond

R-134a's installed base is large and aging. Mobile AC: vehicles built before 2017 (EU) or 2021 (US) use R-134a; this base will service with R-134a through the 2030s as vehicles age out. New vehicles use R-1234yf. Chillers: water-cooled centrifugal chillers installed from 1995-2020 use R-134a; replacement and retrofit decisions through 2030 favor R-513A / R-450A / R-1234ze(E) depending on capital availability.

Domestic refrigeration: the market has been transitioning to R-600a (isobutane) for household refrigerators since the 2010s; R-134a use in new household appliances has largely ended. Commercial refrigeration (vending, beverage coolers, display cases): transitioning to R-1234yf-based low-GWP blends or R-290 (propane) where charge limits permit.

Service-supply economics for R-134a will track the AIM Act production schedule — 70% reduction by 2029, 80% by 2034, 85% by 2036. Reclaimed R-134a will fill an increasing share of the service market. Pricing will rise gradually but stays below the steep curve R-22 has followed since 2020, because the R-134a installed base is much larger and the phase-down is more gradual.

11

Frequently asked

›What is the normal operating pressure of R-134a?

Application-specific. Mobile AC on a hot day: 25-45 PSIG suction, 180-250 PSIG discharge. Residential refrigerator: 1-5 PSIG suction (close to atmospheric), 80-130 PSIG discharge. Centrifugal chiller: 30-50 PSIG suction, 150-200 PSIG discharge.

R-134a saturation at 70°F is 71 PSIG (CoolProp 7.2.0); actual operating values depend on application, ambient, load, and refrigerant charge.

›What does R-134a's GWP of 1430 mean?

Global Warming Potential is a relative atmospheric-warming metric over 100 years against CO₂ (defined as GWP 1). A 1 kg release of R-134a traps approximately 1,430 times more heat than 1 kg of CO₂ over that horizon (IPCC AR5) [ipccar5].

The IPCC AR6 figure (2021) is approximately 1,530 — updated based on improved atmospheric chemistry models. EU F-Gas and US EPA regulation continue to use the AR5 figure (1430) for compliance determinations.

›Why is R-134a being replaced in cars?

GWP. The EU Mobile Air Conditioning Directive 2006/40/EC mandated 150-GWP cap for refrigerants in new MAC vehicle types from 1 January 2017 [eumac]. R-134a's 1430 GWP is well above that threshold.

The chosen MAC replacement is R-1234yf (HFO, A2L, GWP 4). US OEMs transitioned to R-1234yf for most new light-duty vehicles starting around 2017-2021. R-134a remains legal for service of existing MAC systems indefinitely.

›What lubricant does R-134a use?

Depends on application. Stationary HVAC (chillers, commercial refrigeration): polyolester (POE) oil [ahri700]. Mobile AC: polyalkylene glycol (PAG) oil — typically PAG 46 or PAG 100 viscosity grades — for better oil return in variable-displacement automotive compressors [saej639].

Mineral oil and alkylbenzene are NOT miscible with R-134a. Mixing PAG and POE oils in a single system causes oil-return and stability issues.

›Is R-134a the same as Freon?

"Freon" is a Chemours/DuPont trademark applied to many refrigerants over the decades, including R-134a (sold as Suva 134a or, in some markets, simply Freon 134a) [chemoursfreon]. The colloquial use of "Freon" as a generic refrigerant term is technically inaccurate.

Other manufacturers sell the same R-134a under different brand names — Honeywell's Genetron 134a, Solvay's Solkane 134a, etc. All meet the same ASHRAE Standard 34 designation and AHRI Standard 700 purity spec.

›Can I retrofit an R-134a system to R-1234yf?

Mobile AC: not as a refrigerant swap. R-1234yf service ports are different from R-134a (specifically designed to prevent cross-contamination), and the A1-to-A2L safety class change requires vehicle-level safety design. Mobile AC retrofit is rare and economically unjustified.

Stationary chillers: R-134a-to-R-1234yf direct retrofit is not common. The typical chiller path is retrofit to R-513A (A1, GWP 631, near-azeotrope R-134a/R-1234yf blend) or R-450A (A1, GWP 605, R-134a/R-1234ze blend) — both preserve A1 classification and similar pressure envelope.

›Is R-134a still legal in the US?

Yes for now. R-134a remains legal to produce, import, and use in the US under current EPA AIM Act schedules — though it is in active phase-down through the 2030s. Service of existing R-134a equipment is unrestricted; new equipment in some categories (especially mobile AC) has transitioned to lower-GWP alternatives [aimact].

EU regulation is more aggressive — most new MAC vehicles have used R-1234yf since 2017 [eumac].

›What is R-134a used for besides cars?

Centrifugal chillers (water-cooled commercial cooling), domestic refrigeration (household refrigerators historically, though many have transitioned to R-600a isobutane), vending machines and beverage coolers, commercial display refrigeration cases, and some medical inhaler propellants.

The chiller market has been transitioning to R-1234ze(E) (A2L, GWP 7) for new equipment and R-513A / R-450A / R-515B (A1 blends with R-1234yf or R-1234ze) for retrofit. R-134a remains the legacy backbone in the installed base.

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Full PT chart for R-134a · CC BY 4.0 · attribute the source

CSV JSON
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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 — Updated GWP values
    2021https://www.ipcc.ch/report/ar6/wg1/
  4. [4]
    EPA AIM Act — 40 CFR Part 84 Subpart B (HFC Phase-down)
    Final Rule Oct 2021https://www.epa.gov/climate-hfcs-reduction
  5. [5]
    EU Mobile Air Conditioning Directive 2006/40/EC — Banned R-134a in new MAC vehicle types after 1 Jan 2017
    2006 (full ban 1 Jan 2017 for new vehicle types)https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex%3A32006L0040
  6. [6]
    EPA Significant New Alternatives Policy (SNAP) — R-134a end-use determinations
    https://www.epa.gov/snap
  7. [7]
    CoolProp 7.2.0 (Bell, Wronski, Quoilin, Lemort 2014) — REFPROP-compatible Helmholtz EOS
    2014 (continually updated)http://www.coolprop.org/doi:10.1021/ie4033999
  8. [8]
    AHRI Standard 700-2019 — Specifications for Refrigerants
    2019https://www.ahrinet.org/search-standards
  9. [9]
    SAE J639 — Safety Standards for Motor Vehicle Refrigerant Vapor Compression Systems
    https://www.sae.org/standards/content/j639_201407/
  10. [10]
    Chemours Suva 134a / Honeywell Genetron 134a Technical Information
    https://www.chemours.com/en/products/refrigerants
  11. [11]
    NIST Chemistry WebBook — 1,1,1,2-Tetrafluoroethane (CAS 811-97-2)
    https://webbook.nist.gov/chemistry/fluid/

Data sources & provenance

PT chart
CoolProp 7.2.0 R134a
Cross-checked against
CoolProp 7.2.0 (R134a); ASHRAE Handbook of Refrigeration 2022; Chemours Suva 134a datasheet
Properties
CoolProp 7.2.0 + ASHRAE Standard 34-2022
GWP
IPCC AR5 Table 8.A.1
Generated
2026-06-12

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.