HVAC PT Charts
RefrigerantASHRAE R-134a

R134a PT Chart

Updated October 20, 2026

R-134a

A1 Lower toxicity, no flame propagationHFC (pure) AIM Act HFC
R-134a pre-2020 light sky blue service cylinderIllustration of an R-134a cylinder painted light sky blue, the color AHRI Guideline N-2017 lists for R-134a. Label: R134a, safety class A1, GWP 1,430. No red band: AHRI Guideline N-2017 reserves it for flammable refrigerants.R134aA1GWP 1,430
since 2020
R-134a AHRI Guideline N service cylinderIllustration of a refrigerant cylinder painted light green gray (RAL 7044), the color AHRI Guideline N-2017 calls for on all new refrigerant containers from 2020. Label: R134a, safety class A1, GWP 1,430. No red band: AHRI Guideline N-2017 reserves it for flammable refrigerants.R134aA1GWP 1,430
Before 2020, AHRI Guideline N assigned R-134a containers the color light blue (sky, PMS 2975)[15], Table 1. Illustration of a refrigerant cylinder painted light green gray (RAL 7044), the color AHRI Guideline N-2017 calls for on all new refrigerant containers from 2020[15], section 4.8. Label: R-134a, safety class A1, GWP 1,430. No red band: AHRI Guideline N-2017 reserves it for flammable refrigerants[15], section 4.7.
CH2FCF3

Pure HFC-134a (1,1,1,2-tetrafluoroethane)[6], the most common motor-vehicle A/C refrigerant in the US since the 1990s[7], also used in chillers, appliances and medium-temperature refrigeration[8].

R-134a saturation pressure is 35.0 PSIG at 40°F, 71.1 PSIG at 70°F, and 124.2 PSIG at 100°F. These are static saturation pressures. The full table below runs from −40°F to 150°F in 1°F steps. For running pressures by outdoor temperature, see R-134a operating pressures.

Checked against the NIST Chemistry WebBook (SRD 69) saturation data for R-134a[16] at 20 points from −38°F to 148°F: largest difference 0.004 psi.

Saturation @ 70°F
71.1 PSIG
GWP (100-yr)
1,430 AIM Act exchange value (IPCC AR4)
Boiling point
−14.9°F
Sourced facts
ASHRAE safety class
A1[1]
Chemical formula
CH₂FCF₃[1]
GWP (100-yr)
1,430[13]
GWP (AR6)
1,530[2]
ODP
0[18]
Normal boiling point
−14.9°F (−26.1°C)[5]
Critical temperature
213.9°F (101.0°C)[5]
Lubricant
POE / PAG[8]
R-134a PT calculator Operating pressures Superheat

R-134a PT chart — 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).

R-134a PT Chart — Pressure-Temperature Saturation Table

Computed with CoolProp 7.2.0 in 1°F steps · hvacptcharts.com

R-134a · 1° increments · °F / PSIG
Tinted rows: NBP atmospheric crossover · 32°F H₂O freeze
R-134a pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)Pressure (PSIG)
−40°F 14.8 in. Hg vac.
−39°F 14.4 in. Hg vac.
−38°F 13.9 in. Hg vac.
−37°F 13.4 in. Hg vac.
−36°F 13.0 in. Hg vac.
−35°F 12.5 in. Hg vac.
−34°F 12.0 in. Hg vac.
−33°F 11.4 in. Hg vac.
−32°F 10.9 in. Hg vac.
−31°F 10.4 in. Hg vac.
−30°F 9.8 in. Hg vac.
−29°F 9.3 in. Hg vac.
−28°F 8.7 in. Hg vac.
−27°F 8.1 in. Hg vac.
−26°F 7.5 in. Hg vac.
−25°F 6.9 in. Hg vac.
−24°F 6.3 in. Hg vac.
−23°F 5.7 in. Hg vac.
−22°F 5.0 in. Hg vac.
−21°F 4.3 in. Hg vac.
−20°F 3.7 in. Hg vac.
−19°F 3.0 in. Hg vac.
−18°F 2.3 in. Hg vac.
−17°F 1.5 in. Hg vac.
−16°F 0.8 in. Hg vac.
−15°F NBP (atmospheric)0.1 in. Hg vac.
−14°F 0.4
−13°F 0.7
−12°F 1.1
−11°F 1.5
−10°F 1.9
−9°F 2.4
−8°F 2.8
−7°F 3.2
−6°F 3.6
−5°F 4.1
−4°F 4.6
−3°F 5.0
−2°F 5.5
−1°F 6.0
0°F 6.5
1°F 7.0
2°F 7.5
3°F 8.0
4°F 8.5
5°F 9.1
6°F 9.6
7°F 10.2
8°F 10.8
9°F 11.3
10°F 11.9
11°F 12.5
12°F 13.1
13°F 13.8
14°F 14.4
15°F 15.0
16°F 15.7
17°F 16.4
18°F 17.0
19°F 17.7
20°F 18.4
21°F 19.1
22°F 19.9
23°F 20.6
24°F 21.3
25°F 22.1
26°F 22.9
27°F 23.7
28°F 24.5
29°F 25.3
30°F 26.1
31°F 26.9
32°F H₂O freeze27.8
33°F 28.6
34°F 29.5
35°F 30.4
36°F 31.3
37°F 32.2
38°F 33.1
39°F 34.1
40°F 35.0
41°F 36.0
42°F 37.0
43°F 38.0
44°F 39.0
45°F 40.1
46°F 41.1
47°F 42.2
48°F 43.2
49°F 44.3
50°F 45.4
51°F 46.6
52°F 47.7
53°F 48.9
54°F 50.0
55°F 51.2
56°F 52.4
57°F 53.6
58°F 54.9
59°F 56.1
60°F 57.4
61°F 58.7
62°F 60.0
63°F 61.3
64°F 62.7
65°F 64.0
66°F 65.4
67°F 66.8
68°F 68.2
69°F 69.7
70°F 71.1
71°F 72.6
72°F 74.1
73°F 75.6
74°F 77.1
75°F 78.7
76°F 80.2
77°F 81.8
78°F 83.4
79°F 85.0
80°F 86.7
81°F 88.4
82°F 90.0
83°F 91.8
84°F 93.5
85°F 95.2
86°F 97.0
87°F 98.8
88°F 100.6
89°F 102.5
90°F 104.3
91°F 106.2
92°F 108.1
93°F 110.0
94°F 112.0
95°F 113.9
96°F 115.9
97°F 118.0
98°F 120.0
99°F 122.1
100°F 124.2
101°F 126.3
102°F 128.4
103°F 130.6
104°F 132.7
105°F 135.0
106°F 137.2
107°F 139.5
108°F 141.7
109°F 144.0
110°F 146.4
111°F 148.7
112°F 151.1
113°F 153.5
114°F 156.0
115°F 158.4
116°F 160.9
117°F 163.4
118°F 166.0
119°F 168.6
120°F 171.2
121°F 173.8
122°F 176.5
123°F 179.1
124°F 181.8
125°F 184.6
126°F 187.4
127°F 190.1
128°F 193.0
129°F 195.8
130°F 198.7
131°F 201.6
132°F 204.6
133°F 207.5
134°F 210.6
135°F 213.6
136°F 216.7
137°F 219.7
138°F 222.9
139°F 226.0
140°F 229.2
141°F 232.4
142°F 235.7
143°F 239.0
144°F 242.3
145°F 245.7
146°F 249.0
147°F 252.5
148°F 255.9
149°F 259.4
150°F 262.9
CoolProp 7.2.0 · PSIG/kPa = gauge · PSIA = PSIG + 14.6959 · 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 (published Helmholtz equations of state / mixture models — see the source citations above).

A1
Lower toxicity, no flame propagation

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[1], safety group definitions and refrigerant safety classifications. See full reference.

Saturation pressure-temperature curve

Pressure
Temperature
°F
70°F: 71.1 PSIG
Quick lookup — R-134a
71.1PSIG(490 kPa)
Range: −40 to 150°F Open 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[5]. Operating pressure on a running system differs — see what R-134a operating pressures should be.

At a glance

Chemistry

CH2FCF3
1,1,1,2-Tetrafluoroethane

Lubricant compatibility

POEPAGMOAB

POE absorbs water — minimize its contact with air and keep it in a sealed metal container[9], p. 2.

Trade names

  • Freon™ 134a — Chemours[8]

Common applications

  • Automotive air conditioning
  • Appliances
  • Small stationary equipment
  • Medium-temperature supermarket cases
  • Industrial and commercial chillers

Properties

  • Boiling point (1 atm)
    −14.9°F (−26.1°C)
  • Critical point
    213.9°F (101.0°C) at 574 PSIG
  • Molar mass
    102.03 g/mol
  • ODP
    0
  • GWP (100-yr)
    1,430 AIM Act exchange value (IPCC AR4) IPCC: AR4 1,430 · AR5 1,300 · AR6 1,530
  • Atmospheric lifetime
    14 years
  • New-equipment status (US)
    Restricted in 45 new-equipment categories — US new-equipment rules (40 CFR 84.54).

What is R-134a?

R-134a is pure 1,1,1,2-tetrafluoroethane (CH₂FCF₃), a single-molecule HFC with no temperature glide[6]. R-134a has been the most common refrigerant in US motor-vehicle A/C since the 1990s[7].

Regulatory & phase-down status

In the US, 40 CFR 84.54(a)(13) bars manufacture or import of R-134a (GWP ≥150) motor vehicle A/C for Model Year 2025 and later light-duty passenger cars and trucks (effective October 24, 2024); Model Year 2028 and later medium-duty passenger vehicles, heavy-duty pickups and complete heavy-duty vans follow, and certain nonroad vehicles from January 1, 2028[10], §84.54(a)(13)(i)–(iii). New light-duty cars and trucks can't use R-134a from Model Year 2025; 40 CFR 84.54 does not restrict servicing existing vehicles[10].

R-134a is one of the HFCs regulated under the AIM Act[3].

Service notes

Venting it while servicing or disposing of equipment is prohibited under Clean Air Act section 608[11].

Operating cycle

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

Phase-down timeline

R-134a is a regulated substance under the AIM Act[3], 42 U.S.C. 7675(c)(1). Its GWP under 40 CFR 84.64 is 1,430, at or above the limit in 45 of the categories 40 CFR 84.54 restricts (listed under “All 84.54 categories restricting R-134a”).

  • From October 24, 2024 — new motor vehicle air-conditioning in Model Year 2025 and later light-duty passenger cars and trucks (gross vehicle weight rating under 8,500 lb): manufacture / import restricted (GWP ≥ 150)[10], §84.54(a)(13)(i).
  • From January 1, 2025 — new self-contained residential & light-commercial AC and heat pump products: manufacture / import restricted (GWP ≥ 700)[10], §84.54(a)(1).
  • From January 1, 2025 — new chillers for comfort cooling: manufacture / import restricted (GWP ≥ 700)[10], §84.54(a)(10)(i).
  • From January 1, 2025 — new residential & light-commercial AC and heat pump systems (except VRF): installation restricted (GWP ≥ 700), unless every specified component was manufactured or imported before January 1, 2025[10], §84.54(c)(1).
  • From January 1, 2025 — new chillers for comfort cooling: installation restricted (GWP ≥ 700)[10], §84.54(c)(3).
  • From January 1, 2026 — new chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C): manufacture / import restricted (GWP ≥ 700)[10], §84.54(a)(10)(iii).
  • From January 1, 2026 — new variable refrigerant flow (VRF) residential & light-commercial AC and heat pump systems: installation restricted (GWP ≥ 700); systems whose specified components were all manufactured or imported before January 1, 2026 may be installed until January 1, 2027, or until January 1, 2028 when a building permit issued before October 5, 2023 specifies the refrigerant[10], §84.54(c)(2).
  • From January 1, 2026 — new chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C): installation restricted (GWP ≥ 700)[10], §84.54(c)(5)(i).
  • From January 1, 2027 — new supermarket systems: installation restricted (GWP ≥ 1,400)[10], §84.54(c)(12)(i).
  • From January 1, 2028 — new chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C): manufacture / import restricted (GWP ≥ 700)[10], §84.54(a)(10)(iv).
  • From Model Year 2028 — new motor vehicle air-conditioning in medium-duty passenger vehicles, heavy-duty pickup trucks and complete heavy-duty vans whose air-conditioning will not be modified by upfitters: manufacture / import restricted (GWP ≥ 150)[10], §84.54(a)(13)(ii).
  • From January 1, 2028 — new motor vehicle air-conditioning in certain nonroad vehicles (agricultural tractors over 40 horsepower; self-propelled agricultural machinery; compact equipment; construction, forestry and mining equipment; and commercial utility vehicles): manufacture / import restricted (GWP ≥ 150)[10], §84.54(a)(13)(iii).
  • From January 1, 2028 — new self-contained residential & light-commercial AC and heat pump products: sale and distribution restricted (GWP ≥ 700)[10], §84.54(b).
  • From January 1, 2028 — new chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C): installation restricted (GWP ≥ 700)[10], §84.54(c)(6)(i).
  • From January 1, 2032 — new supermarket systems: installation restricted at GWP ≥ 150 for systems with 200 lb or more of refrigerant (except the high-temperature side of a cascade system), and at GWP ≥ 300 for systems under 200 lb and for the high-temperature side of a cascade system[10], §84.54(c)(12)(ii).

HFC production & consumption allowances step down to 30% of baseline in 2029–2033, 20% of baseline in 2034–2035, and 15% of baseline in 2036 and later (42 U.S.C. 7675(e)(2)(C))[3].

Full 40 CFR 84.54 new-equipment rules for R-134a →

US new-equipment rules (40 CFR 84.54)

R-134a is a regulated substance under the AIM Act[3], 42 U.S.C. 7675(c)(1). Under 40 CFR 84.64(a) its GWP is 1,430, the AIM Act exchange value. That value is compared against each 40 CFR 84.54 subsector limit below.

EffectiveEquipment subsectorLimitRestriction
October 24, 2024Motor vehicle air-conditioning in Model Year 2025 and later light-duty passenger cars and trucks (gross vehicle weight rating under 8,500 lb)GWP ≥ 150Manufacture / import(a)(13)(i)
January 1, 2025Self-contained residential & light-commercial AC and heat pump productsGWP ≥ 700Manufacture / import(a)(1)
January 1, 2025Chillers for comfort coolingGWP ≥ 700Manufacture / import(a)(10)(i)
January 1, 2025Residential & light-commercial AC and heat pump systems (except VRF)GWP ≥ 700Installation(c)(1)
January 1, 2025Chillers for comfort coolingGWP ≥ 700Installation(c)(3)
January 1, 2026Chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C)GWP ≥ 700Manufacture / import(a)(10)(iii)
January 1, 2026Variable refrigerant flow (VRF) residential & light-commercial AC and heat pump systemsGWP ≥ 700Installation(c)(2)
January 1, 2026Chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C)GWP ≥ 700Installation(c)(5)(i)
January 1, 2027Supermarket systemsGWP ≥ 1,400Installation(c)(12)(i)
October 24, 2027Motor vehicle air-conditioning in Model Year 2025 and later light-duty passenger cars and trucks (gross vehicle weight rating under 8,500 lb)GWP ≥ 150Sale / distribution(b)
January 1, 2028Chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700Manufacture / import(a)(10)(iv)
Model Year 2028Motor vehicle air-conditioning in medium-duty passenger vehicles, heavy-duty pickup trucks and complete heavy-duty vans whose air-conditioning will not be modified by upfittersGWP ≥ 150Manufacture / import(a)(13)(ii)
January 1, 2028Motor vehicle air-conditioning in certain nonroad vehicles (agricultural tractors over 40 horsepower; self-propelled agricultural machinery; compact equipment; construction, forestry and mining equipment; and commercial utility vehicles)GWP ≥ 150Manufacture / import(a)(13)(iii)
January 1, 2028Self-contained residential & light-commercial AC and heat pump productsGWP ≥ 700Sale / distribution(b)
January 1, 2028Chillers for comfort coolingGWP ≥ 700Sale / distribution(b)
January 1, 2028Chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700Installation(c)(6)(i)
January 1, 2029Chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C)GWP ≥ 700Sale / distribution(b)
January 1, 2031Chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700Sale / distribution(b)
January 1, 2031Motor vehicle air-conditioning in certain nonroad vehicles (agricultural tractors over 40 horsepower; self-propelled agricultural machinery; compact equipment; construction, forestry and mining equipment; and commercial utility vehicles)GWP ≥ 150Sale / distribution(b)
January 1, 2032Supermarket systemsGWP ≥ 150 (200 lb or greater, not the cascade high side); GWP ≥ 300 (less than 200 lb); GWP ≥ 300 (cascade high side)Installation(c)(12)(ii)
All 84.54 categories restricting R-134a (45)[10]
Refrigeration, air conditioning & heat pumps (38)
January 1, 2025Self-contained residential & light-commercial AC and heat pump productsGWP ≥ 700(a)(1)
January 1, 2025Chillers for comfort coolingGWP ≥ 700(a)(10)(i)
January 1, 2025Chillers for ice rinksGWP ≥ 700(a)(10)(ii)
January 1, 2025Residential dehumidifiersGWP ≥ 700(a)(2)
January 1, 2025Household refrigerators and freezersGWP ≥ 150(a)(3)
January 1, 2025Retail food refrigeration — stand-alone unitsGWP ≥ 150(a)(4)
January 1, 2025Vending machinesGWP ≥ 150(a)(5)
January 1, 2025Residential & light-commercial AC and heat pump systems (except VRF)GWP ≥ 700(c)(1)
January 1, 2025Chillers for comfort coolingGWP ≥ 700(c)(3)
January 1, 2025Ice rinksGWP ≥ 700(c)(4)
January 1, 2026Chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C)GWP ≥ 700(a)(10)(iii)
January 1, 2026Industrial process refrigeration products (non-chiller), charge 200 lb or greater, refrigerant entering the evaporator warmer than −22°F (−30°C)GWP ≥ 150(a)(12)(i)
January 1, 2026Industrial process refrigeration products (non-chiller), charge less than 200 lb, refrigerant entering the evaporator warmer than −22°F (−30°C)GWP ≥ 300(a)(12)(ii)
January 1, 2026Ice makers — batch type up to 1,000 lb of ice per 24 h and continuous type up to 1,200 lb per 24 hGWP ≥ 150(a)(8)(i)
January 1, 2026Industrial process refrigeration systems (non-chiller), charge 200 lb or greater, evaporator inlet warmer than −22°F (−30°C), not the high-temperature side of a cascadeGWP ≥ 150(c)(10)(i)
January 1, 2026Industrial process refrigeration systems (non-chiller), charge less than 200 lb, evaporator inlet warmer than −22°F (−30°C)GWP ≥ 300(c)(10)(ii)
January 1, 2026Industrial process refrigeration — high-temperature side of cascade systems, evaporator inlet warmer than −22°F (−30°C)GWP ≥ 300(c)(10)(iii)
January 1, 2026Variable refrigerant flow (VRF) residential & light-commercial AC and heat pump systemsGWP ≥ 700(c)(2)
January 1, 2026Chillers for industrial process refrigeration, fluid exiting the chiller warmer than −22°F (−30°C)GWP ≥ 700(c)(5)(i)
July 27, 2026Refrigerated transport — intermodal containers with a box temperature of −31°F (−35°C) or higherGWP ≥ 700(a)(6)
July 27, 2026Retail food refrigeration — remote condensing unitsGWP ≥ 1,400(c)(11)(i)
July 27, 2026Refrigerated transport — intermodal containers with a box temperature of −31°F (−35°C) or higherGWP ≥ 700(c)(7)
July 27, 2026Cold storage warehouse systemsGWP ≥ 700(c)(9)(i)
January 1, 2027Self-contained products in data center, information technology equipment facility, and computer room coolingGWP ≥ 700(a)(11)
January 1, 2027Ice makers — batch type above 1,000 lb of ice per 24 h and continuous type above 1,200 lb per 24 hlisted refrigerant(a)(8)(ii)
January 1, 2027Refrigerated food processing and dispensing products outside the scope of UL 621, charge 500 g or lessGWP ≥ 150(a)(9)(i)
January 1, 2027Refrigerated food processing and dispensing products outside the scope of UL 621, charge greater than 500 glisted refrigerant(a)(9)(ii)
January 1, 2027Supermarket systemsGWP ≥ 1,400(c)(12)(i)
January 1, 2027Data center, information technology equipment facility, and computer room cooling systemsGWP ≥ 700(c)(13)
January 1, 2027Refrigerated food processing and dispensing equipment with a remote condenserlisted refrigerant(c)(15)
January 1, 2028Chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700(a)(10)(iv)
January 1, 2028Industrial process refrigeration products (non-chiller), refrigerant entering the evaporator from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700(a)(12)(iii)
January 1, 2028Refrigerated food processing and dispensing products within the scope of UL 621 (ice cream makers)listed refrigerant(a)(9)(iii)
January 1, 2028Industrial process refrigeration systems (non-chiller), evaporator inlet from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700(c)(10)(iv)
January 1, 2028Chillers for industrial process refrigeration, fluid exiting the chiller from −58°F to −22°F (−50°C to −30°C)GWP ≥ 700(c)(6)(i)
January 1, 2032Retail food refrigeration — remote condensing unitsGWP ≥ 150 (200 lb or greater, not the cascade high side); GWP ≥ 300 (less than 200 lb); GWP ≥ 300 (cascade high side)(c)(11)(ii)
January 1, 2032Supermarket systemsGWP ≥ 150 (200 lb or greater, not the cascade high side); GWP ≥ 300 (less than 200 lb); GWP ≥ 300 (cascade high side)(c)(12)(ii)
January 1, 2032Cold storage warehouse systemsGWP ≥ 150 (200 lb or greater, not the cascade high side); GWP ≥ 300 (less than 200 lb); GWP ≥ 300 (cascade high side)(c)(9)(ii)
Motor vehicle air conditioning (3)
October 24, 2024Motor vehicle air-conditioning in Model Year 2025 and later light-duty passenger cars and trucks (gross vehicle weight rating under 8,500 lb)GWP ≥ 150(a)(13)(i)
Model Year 2028Motor vehicle air-conditioning in medium-duty passenger vehicles, heavy-duty pickup trucks and complete heavy-duty vans whose air-conditioning will not be modified by upfittersGWP ≥ 150(a)(13)(ii)
January 1, 2028Motor vehicle air-conditioning in certain nonroad vehicles (agricultural tractors over 40 horsepower; self-propelled agricultural machinery; compact equipment; construction, forestry and mining equipment; and commercial utility vehicles)GWP ≥ 150(a)(13)(iii)
Foam blowing agents (2)
January 1, 2025Foam products: rigid polyurethane appliance foam, commercial refrigeration foam, laminated boardstock, marine flotation foam, sandwich panels, slabstock; flexible polyurethane; integral skin polyurethane; polystyrene (extruded boardstock, billet, extruded sheet); phenolic insulation board and bunstock; polyisocyanurate laminated boardstock; polyolefin; rigid polyurethane spray foamGWP ≥ 150(a)(14)
January 1, 2026Foam products in the (a)(14) formulations for use in space and military applicationsGWP ≥ 150(a)(15)
Aerosol propellants / solvents (2)
January 1, 2025Aerosol productsGWP ≥ 150(a)(16)(i)
January 1, 2028Aerosol products (all, except defense sprays as defined in 84.3)GWP ≥ 150(a)(16)(ii)

Servicing. 40 CFR 84.54 restricts new manufacture/import, later sale/distribution, and installation. "Installation" is defined in 84.54(e); repairing or servicing existing R-134a equipment is not an installation unless it meets 84.54(e), so existing systems can keep being serviced. From January 1, 2029, servicing or repairing R-134a equipment in supermarket systems, refrigerated transport or automatic commercial ice makers must be done with reclaimed refrigerant[17].

EU (retail-food / cold-storage)

Under Regulation (EU) No 517/2014, since replaced by (EU) 2024/573, applying from March 11, 2024 (compared against the AR4 headline GWP), R-134a's GWP is at or above the limit in:

  • Annex III row 11: Refrigerators and freezers for commercial use (hermetically sealed equipment) — GWP ≥ 150, from January 1, 2022.
  • Annex III row 13: Multipack centralised refrigeration systems for commercial use with a rated capacity of 40 kW or more — GWP ≥ 150, from January 1, 2022 (the primary refrigerant circuit of a cascade system may use GWP below 1,500).

Regulation (EU) No 517/2014.

Source: 40 CFR 84.54, current through 91 FR 31329 (May 26, 2026). Installation defined at 40 CFR 84.54(e).

Global warming potential, in context

Medium-pressure centrifugal & screw chillers

R-1234ze1R-1234ze(E)1R-515B287R-515A387R-450A601R-513A630R-134a1.4k

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[1]. 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 temperature − saturation temperature at suction pressure; subcooling = saturation temperature at liquid-line pressure − liquid-line temperature. No glide correction needed across any application.

Why pure refrigerant chemistry matters in service

R-134a's single-component nature means it cannot fractionate during partial charging or leaking.

R-134a vs R-12, R-1234yf, R-513A, R-450A: saturation pressure

Saturation pressure (PSIG, gauge) for R-134a vs R-12, R-1234yf, R-513A, R-450A — zeotropic blends shown as dew / bubble. Each column shows the percent difference from R-134a. Sources: R-134a, R-12, R-1234yf and R-513A: CoolProp 7.2.0 dataset; R-450A: CoolProp 8.0.0 dataset.
TempR-134aR-12R-1234yfR-513AR-450A
0°F6.59.19.29.43.8 / 4.3
40°F35.036.9(+5%)38.4(+10%)39.8(+14%)28.9 / 29.8(−15%)
70°F71.170.1(−1%)73.9(+4%)77.2(+9%)60.6 / 62.0(−13%)
100°F124.2116.9(−6%)124.9(+1%)131.4(+6%)107.3 / 109.3(−12%)

Frequently asked

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

Operating pressure depends on evaporator load and ambient; for suction and discharge by outdoor temperature, see What pressure should R-134a be?. The saturation pressures are in the PT table and the comparison table on this page.

›What does R-134a's GWP of 1,430 mean?

GWP compares how much energy 1 ton of a gas absorbs over a given period (usually 100 years) with 1 ton of CO₂, which has a GWP of 1 by definition[12]. On the US EPA basis R-134a's GWP is 1,430, so releasing 1 kg absorbs about 1,430 times as much energy over 100 years as releasing 1 kg of CO₂[13][12].

IPCC AR6 gives 1,530[2]. US EPA compliance uses 1,430 for R-134a[13].

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

GWP. In the EU, Directive 2006/40/EC bars air conditioning designed for refrigerants with GWP above 150 in new vehicle types from January 1, 2011 and in all new cars and light vans (categories M1 and N1 class I) from January 1, 2017[4]. R-134a's GWP of 1,430 is above that limit[13].

EPA lists R-1234yf as acceptable, subject to use conditions, for new passenger cars and light-duty trucks[7]. In the US, 40 CFR 84.54(a)(13) bars refrigerants with a GWP of 150 or more (R-134a included) in new light-duty cars and trucks from Model Year 2025 (effective October 24, 2024), in medium-duty passenger vehicles, heavy-duty pickups and complete heavy-duty vans from Model Year 2028, and in certain nonroad vehicles from January 1, 2028[10], §84.54(a)(13)(i)–(iii). 40 CFR 84.54 does not restrict servicing existing vehicle A/C systems[10].

›What lubricant does R-134a use?

Use the oil the vehicle or equipment maker specifies. Chemours reports good solubility in R-134a for POE oils and low-viscosity PAG oils, and very poor solubility for mineral oil and alkylbenzene[8].

Mineral oil and alkylbenzene have very poor solubility in R-134a[8].

›Is R-134a the same as Freon?

Freon™ is a Chemours trademark; Chemours sells R-134a as Freon™ 134a[8].

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

Not as a straight swap. EPA lists R-1234yf for new passenger cars and light-duty trucks, and its use conditions require SAE J639 safety features, including unique service fittings[7][14]. R-1234yf systems use unique service fittings consistent with SAE J639 (17 mm high side, 14 mm low side)[14].

›Is R-134a still legal in the US?

Yes. R-134a can still be produced, imported and used in the US within the AIM Act allowances, which step down to 15% of baseline from 2036[3]; 40 CFR 84.54 limits it only in certain new equipment[10].

In the EU, Directive 2006/40/EC bars air conditioning designed for refrigerants with GWP above 150 in new vehicle types from January 1, 2011 and in all new cars and light vans (categories M1 and N1 class I) from January 1, 2017[4].

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

Chemours lists appliances, small stationary equipment, medium-temperature supermarket cases, industrial and commercial chillers, foam blowing and aerosol products[8].

Download this dataset

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

CSV JSON

Sources & citations

  1. [1]
    ANSI/ASHRAE Standard 34-2022, Designation and Safety Classification of Refrigerants (free read-only version). ASHRAE. 2022. https://www.ashrae.org/technical-resources/standards-and-guidelines/read-only-versions-of-ashrae-standards (accessed October 2, 2026)
  2. [2]
    IPCC AR6 WG1 (2021), Chapter 7, Supplementary Material, Table 7.SM.7. IPCC AR6 Working Group I. 2021. https://www.ipcc.ch/report/ar6/wg1/ (accessed October 2, 2026)
  3. [3]
    42 U.S.C. 7675 — American Innovation and Manufacturing Act. US Code (via Cornell LII). current. https://www.law.cornell.edu/uscode/text/42/7675 (accessed October 2, 2026)
  4. [4]
    Directive 2006/40/EC (MAC Directive). EUR-Lex. OJ L 161, 14.6.2006. https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32006L0040 (accessed October 2, 2026)
  5. [5]
    CoolProp 7.2.0. CoolProp (I. H. Bell, J. Wronski, S. Quoilin, V. Lemort). https://coolprop.org/ (accessed October 2, 2026). Bell, I. H.; Wronski, J.; Quoilin, S.; Lemort, V. Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp. Ind. Eng. Chem. Res. 53, 2498–2508 (2014). https://doi.org/10.1021/ie4033999
  6. [6]
    ASHRAE Refrigerant Designations. ASHRAE. web page, updated May 25, 2021. https://www.ashrae.org/technical-resources/standards-and-guidelines/ashrae-refrigerant-designations (accessed October 2, 2026)
  7. [7]
    Acceptable Refrigerants and their Impacts (motor vehicle A/C). US EPA. last updated April 28, 2026. https://www.epa.gov/mvac/acceptable-refrigerants-and-their-impacts (accessed October 2, 2026)
  8. [8]
    Freon™ 134a Refrigerant (R-134a) Properties, Uses, Storage, and Handling. Chemours. C-11062 (7/26). https://www.freon.com/en/-/media/files/freon/freon-134a-push-bulletin.pdf (accessed October 2, 2026)
  9. [9]
    Freon™ 407C Refrigerant (R-407C) Retrofit Guidelines. Chemours. C-11107 (2/17). https://www.freon.com/en/-/media/files/freon/freon-407c-retrofit-guidelines.pdf (accessed October 2, 2026)
  10. [10]
    40 CFR 84.54 — Restrictions on the use of hydrofluorocarbons. eCFR (Office of the Federal Register). up to date as of 9/29/2026. https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-84/subpart-B/section-84.54 (accessed October 2, 2026)
  11. [11]
    Stationary Refrigeration — Prohibition on Venting Refrigerants. US EPA. last updated December 8, 2025. https://www.epa.gov/section608/stationary-refrigeration-prohibition-venting-refrigerants (accessed October 2, 2026)
  12. [12]
    Understanding Global Warming Potentials. US EPA. last updated December 29, 2025. https://www.epa.gov/ghgemissions/understanding-global-warming-potentials (accessed October 2, 2026)
  13. [13]
    Technology Transitions GWP Reference Table. US EPA. updated April 2, 2026. https://www.epa.gov/hfcs/technology-transitions-gwp-reference-table (accessed October 2, 2026)
  14. [14]
    Unique Fittings and Label Colors. US EPA. last updated June 8, 2026. https://www.epa.gov/mvac/unique-fittings-and-label-colors (accessed October 2, 2026)
  15. [15]
    2017 Guideline for Assignment of Refrigerant Container Colors (AHRI Guideline N-2017). AHRI. 2017. https://www.ahrinet.org/system/files/2023-06/AHRI_Guideline_N_2017.pdf (accessed October 2, 2026)
  16. [16]
    NIST Chemistry WebBook (SRD 69) saturation data for R-134a. NIST. https://webbook.nist.gov/cgi/fluid.cgi?TLow=-40&THigh=150&TInc=10&Digits=6&ID=C811972&Action=Load&Type=SatT&TUnit=F&PUnit=psia&DUnit=lbm%2Fft3&HUnit=Btu%2Flbm&WUnit=ft%2Fs&VisUnit=uPa*s&STUnit=lb%2Fin&RefState=DEF (accessed October 2, 2026). NIST reference equation of state for this fluid
  17. [17]
    40 CFR 84.112 — Reclamation. eCFR (Office of the Federal Register). up to date as of 9/25/2026. https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-84/subpart-C/section-84.112 (accessed October 2, 2026). 89 FR 82859, Oct. 11, 2024
  18. [18]
    Substitutes in Typical Supermarket Systems. US EPA (SNAP). last updated March 20, 2026. https://www.epa.gov/snap/substitutes-typical-supermarket-systems (accessed October 5, 2026)

Data sources & provenance

PT chart
CoolProp 7.2.0
Cross-checked against
NIST Chemistry WebBook (SRD 69) saturation data for R-134a[16]
Properties
CoolProp 7.2.0 + ASHRAE Standard 34-2022
GWP (100-yr)
AIM Act exchange value (IPCC AR4) · IPCC AR4/AR5/AR6 on the GWP rankings
Table computed
October 2026

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. See how this PT table is calculated and independently checked in our methodology.