HVAC PT ChartsVerified saturation data · 61 refrigerants
RefrigerantASHRAE R-290

R-290

A3Highly flammableHydrocarbon
C3H8

Pure propane (C₃H₈) — natural hydrocarbon refrigerant with GWP 3, zero ODP, A3 highly flammable. Growing in heat pumps and small commercial refrigeration under strict charge limits per IEC 60335-2-40/89.

Saturation @ 70°F
110.2PSIG
GWP (IPCC AR5)
3100-yr
Temperature glide
≈0°F
Boiling point
-43.8°F
Sourced facts
ASHRAE safety class
A3[src]
Chemical formula
C₃H₈[src]
GWP (100-yr)
3IPCC AR5[src]
ODP
0[src]
Normal boiling point
−43.8°F (−42.1°C)[src]
Critical temperature
206.1°F (96.7°C)[src]
Saturation @ 70°F
110PSIG[src]
Residential charge limit
≈500g (typical, application-dependent)[src]
R-290 PT calculator Superheat
A3
Highly flammable

Lower toxicity. High burning velocity (> 100 cm/s) or high heat of combustion. Includes hydrocarbons R-290 (propane), R-600a (isobutane), R-1150 (ethylene), R-1270 (propylene). EPA charge limits, HC-rated equipment design, sealed systems, and leak detection are mandatory.

Flammability
High (burning velocity > 100 cm/s)
Toxicity
Lower

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

01

Saturation pressure-temperature curve

Pressure
Temperature
°F
70°F: 110.2 PSIG
Quick lookup — R-290
110.2PSIG(760 kPa)
Range: -40 to 150°FOpen full PT calculator →
Common service temperatures
32°F
54PSIG
Freezing
45°F
71PSIG
Heat-pump heat
70°F
110PSIG
Standard
75°F
120PSIG
Test ref
80°F
129PSIG
Warm
95°F
162PSIG
Summer peak

Saturation values from CoolProp 7.2.0 Propane. Operating pressure on a running system differs — see the operating-pressure references for in-use values.

02

R-290 PT chart PDF — printable saturation table

Looking for the R-290 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-290 PT Chart — Pressure-Temperature Saturation Table

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

R-290 · 1° increments · °F / PSIG
Tinted rows: 32°F H₂O freeze · 0°F Freezer compartment · 40°F Fridge compartment · 90°F Hot day ambient
R-290 pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)Pressure (PSIG)
-40°F1.4
-39°F1.8
-38°F2.2
-37°F2.6
-36°F3.0
-35°F3.5
-34°F3.9
-33°F4.3
-32°F4.8
-31°F5.2
-30°F5.7
-29°F6.1
-28°F6.6
-27°F7.1
-26°F7.6
-25°F8.1
-24°F8.6
-23°F9.1
-22°F9.7
-21°F10.2
-20°F10.7
-19°F11.3
-18°F11.8
-17°F12.4
-16°F13.0
-15°F13.6
-14°F14.2
-13°F14.8
-12°F15.4
-11°F16.1
-10°F16.7
-9°F17.4
-8°F18.0
-7°F18.7
-6°F19.4
-5°F20.1
-4°F20.8
-3°F21.5
-2°F22.2
-1°F22.9
0°FFreezer compartment23.7
1°F24.4
2°F25.2
3°F26.0
4°F26.8
5°F27.6
6°F28.4
7°F29.2
8°F30.1
9°F30.9
10°F31.8
11°F32.7
12°F33.6
13°F34.5
14°F35.4
15°F36.3
16°F37.3
17°F38.2
18°F39.2
19°F40.1
20°F41.1
21°F42.1
22°F43.2
23°F44.2
24°F45.2
25°F46.3
26°F47.4
27°F48.5
28°F49.6
29°F50.7
30°F51.8
31°F53.0
32°FH₂O freeze54.1
33°F55.3
34°F56.5
35°F57.7
36°F58.9
37°F60.1
38°F61.4
39°F62.7
40°FFridge compartment63.9
41°F65.2
42°F66.5
43°F67.9
44°F69.2
45°F70.6
46°F72.0
47°F73.3
48°F74.8
49°F76.2
50°F77.6
51°F79.1
52°F80.6
53°F82.1
54°F83.6
55°F85.1
56°F86.7
57°F88.2
58°F89.8
59°F91.4
60°F93.0
61°F94.7
62°F96.3
63°F98.0
64°F99.7
65°F101.4
66°F103.1
67°F104.9
68°F106.6
69°F108.4
70°F110.2
71°F112.0
72°F113.9
73°F115.7
74°F117.6
75°F119.5
76°F121.5
77°F123.4
78°F125.3
79°F127.3
80°F129.3
81°F131.4
82°F133.4
83°F135.5
84°F137.6
85°F139.7
86°F141.8
87°F143.9
88°F146.1
89°F148.3
90°FHot day ambient150.5
91°F152.8
92°F155.0
93°F157.3
94°F159.6
95°F161.9
96°F164.3
97°F166.7
98°F169.1
99°F171.5
100°F173.9
101°F176.4
102°F178.9
103°F181.4
104°F183.9
105°F186.5
106°F189.1
107°F191.7
108°F194.3
109°F197.0
110°F199.6
111°F202.3
112°F205.1
113°F207.8
114°F210.6
115°F213.4
116°F216.3
117°F219.1
118°F222.0
119°F224.9
120°F227.8
121°F230.8
122°F233.8
123°F236.8
124°F239.9
125°F242.9
126°F246.0
127°F249.2
128°F252.3
129°F255.5
130°F258.7
131°F261.9
132°F265.2
133°F268.5
134°F271.8
135°F275.1
136°F278.5
137°F281.9
138°F285.4
139°F288.8
140°F292.3
141°F295.8
142°F299.4
143°F303.0
144°F306.6
145°F310.2
146°F313.9
147°F317.6
148°F321.4
149°F325.1
150°F328.9
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-290 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

C3H8
Propane

Lubricant compatibility

MOABPAOPOE

Highly flammable (A3). EPA charge limits apply: 150 g for household refrigerators, increasing limits for commercial under updated SNAP rules. HC-rated equipment design with sealed systems and leak detection is mandatory.

Trade names

  • Care 40Care Refrigerants

Common applications

  • Household refrigerators and freezers (Europe widely; US increasingly)
  • Small commercial refrigeration (display cases, ice machines)
  • Heat pumps (small residential, R-290 monobloc designs growing)
04

Properties

  • Boiling point (1 atm)
    -42.1°C / -43.8°F
  • Critical point
    206.1°F at 602 PSIG
  • Molar mass
    44.10 g/mol
  • Temperature glide
    Negligible (0.00°F)
  • ODP
    0
  • GWP (AR5, 100-yr)
    3
  • GWP (AR6, 100-yr)
    0.072
  • Atmospheric lifetime
    0.04 years
05

What is R-290?

R-290 is pure propane (C₃H₈) — a natural hydrocarbon refrigerant with GWP 3, zero ODP, and A3 (highly flammable) safety classification [ashrae34][ipccar5]. It is a single-component refrigerant with no temperature glide, used historically in industrial refrigeration and increasingly in residential heat pumps and small commercial refrigeration as climate policy pressures HFC alternatives.

R-290's defining trade-off is environmental excellence against operational safety constraints. The GWP is so low it imposes no phase-down risk, but the A3 flammability triggers strict equipment charge limits under IEC 60335-2-40 (heat pumps and AC) and IEC 60335-2-89 (commercial refrigeration). New equipment must be specifically designed for R-290 — sealed motors, no internal ignition sources, refrigerant detection in some installations, charge volume scaled to enclosed space.

Where R-290 is used

  • Residential heat pumps (R-290 monobloc air-source units common in EU)
  • Small commercial refrigeration — bottle coolers, vending machines, ice machines
  • Industrial refrigeration — large process applications with engineered safety controls
  • Domestic refrigeration in some markets (Europe predominantly uses R-600a; R-290 in larger units)

Regulatory & phase-down status

R-290 faces no phase-down — GWP 3 is below any regulatory threshold. EU F-Gas Regulation and EPA AIM Act target high-GWP HFCs; R-290 is a natural refrigerant outside those frameworks [epasnap].

Market growth is driven primarily by heat pump expansion in EU markets (R-290 dominant in many monobloc heat pump categories) and by ongoing displacement of HFCs in small commercial refrigeration. US adoption has been slower due to historically conservative charge limits, though IEC 60335 amendments through 2019-2022 raised allowable charges for many residential applications, accelerating R-290 deployment.

Service notes

R-290 is highly flammable — concentrations of 2.1% to 9.5% in air ignite readily. Equipment design and service procedures must eliminate all potential ignition sources. Sealed compressor motors, electrical components physically separated from the refrigerant circuit, brazing only with refrigerant fully recovered and the system inerted with nitrogen.

Standard HVAC manifold gauges work for R-290 pressure-wise (moderate envelope, 110 PSIG at 70°F). Lubricant is typically mineral oil or alkylbenzene (compatible with hydrocarbons); POE is incompatible. Recovery cylinders must be hydrocarbon-rated and grounded against static discharge during transfer.

EPA Section 608 covers R-290 service; HC-specific training is increasingly required by equipment OEMs and by some states. Charge limits per IEC 60335-2-40/89 are equipment-specific — verify against the equipment data plate before adding refrigerant [iec60335240][iec60335289].

07

Operating cycle

CompressorRaises pressureCondenserRejects heat to outdoorsExpansion deviceDrops pressureEvaporatorAbsorbs heat from indoorsDischarge: 200 PSIG, 180°FLiquid: 200 PSIG, 100°FEvap inlet: 64 PSIG, 40°F (two-phase)Suction: 64 PSIG, 50°FTypical residential cooling cycle for R-290 (40°F evap, 110°F condenser, 10°F superheat, 10°F subcooling)
08

Phase-down timeline

R-290 is not currently regulated by AIM Act or EU F-Gas phase-down. Its very low GWP (3) places it below regulatory thresholds. No published phase-down milestones exist for this refrigerant — it is a forward-compatible option for the current low-GWP transition rather than a refrigerant being phased out.

Properties: GWP (AR5) 3 · ODP 0 · Not AIM Act-affected · type: hc
09

Global warming potential, in context

Household refrigeration

R-600a3R-2903R-134a1.4kR-1211kEU F-Gas (150)EPA AIM Act (700)
10

Retrofit and replacement paths

R-290 replaces

Reading the R-290 pressure-temperature chart

R-290's PT chart is a single saturation curve — R-290 is pure propane with no temperature glide and no bubble/dew distinction [ashrae34]. Read across from temperature to saturation pressure or vice versa, identically to R-22, R-32, or R-134a.

The pressure envelope is moderate — lower than R-22 across the operating range. At 70°F R-290 saturation is approximately 110 PSIG (CoolProp 7.2.0) compared to R-22's 121 PSIG; at 95°F outdoor design ambient, R-290 saturation is approximately 175 PSIG compared to R-22's 181 PSIG. Standard 500 PSI manifold gauges handle R-290 with comfortable margin.

Pure hydrocarbon = simple chemistry, clean PT behavior

R-290 has no glide because it is a single-component substance. The simplicity helps service: no bubble/dew curve distinction, no fractionation concern during partial charging, no composition shift in leaking systems. The complications are operational (A3 flammability charge limits), not thermodynamic.

R-290 pressure envelope is similar to R-22 — convenient but not identical

R-290 and R-22 have similar saturation pressures across the residential operating range because both have similar normal boiling points (R-290: −43.8°F; R-22: −41.5°F per CoolProp 7.2.0) and both are pure single-component refrigerants. The pressure delta between them is typically under 10% across temperatures from −40°F to 120°F.

This pressure similarity made R-290 attractive as an R-22 replacement candidate in industrial refrigeration during the Montreal Protocol R-22 phase-out — same equipment pressure envelope, much better environmental profile, but the A3 flammability classification limited residential deployment. The compromise solution for residential AC was HFCs (R-410A, R-32) rather than hydrocarbons.

For service technicians familiar with R-22, R-290 pressures feel similar but the safety procedures are entirely different. R-22 is A1 non-flammable; R-290 is A3 highly flammable. Equipment design and service procedures must reflect the classification difference even though the pressure envelope is similar.

Propane chemistry — three-carbon hydrocarbon, no halogen

R-290 is propane: a three-carbon hydrocarbon chain saturated with hydrogen (C₃H₈) [ashrae34]. Molar mass is 44.1 g/mol — coincidentally similar to R-744 (CO₂, 44 g/mol) but with completely different chemistry and refrigeration behavior.

The chemistry is fundamentally different from fluorocarbon refrigerants. Propane is non-toxic, has no chlorine, no fluorine, no atmospheric persistence beyond a few weeks. Atmospheric breakdown by OH radicals is fast — the atmospheric lifetime is approximately 12 days. The short lifetime is what gives R-290 its very low GWP (3 per IPCC AR5).

Same chemistry as fuel propane, refrigerant-grade purity

R-290 is chemically identical to LPG (liquefied petroleum gas) propane used as fuel for grills, generators, and forklifts. The differences are purity (refrigerant-grade specified at ≥99.5% per AHRI 700), absence of odorants (refrigerant grade has no ethyl mercaptan), and controlled moisture content [ahri700]. Never use fuel-grade propane as a refrigerant — the impurities damage compressor lubrication.

Environmental profile — among the best of any commercial refrigerant

R-290 has zero ozone-depletion potential (no chlorine in the molecule) and GWP 3 per IPCC AR5 [ipccar5]. Combined with its short atmospheric lifetime (~12 days, vs decades for HFCs), R-290's environmental footprint is among the smallest possible for a commercial refrigerant.

For comparison: R-22 (HCFC) has ODP 0.055 and GWP 1810; R-410A (HFC) has ODP 0 and GWP 2088; R-404A (HFC) has ODP 0 and GWP 3922. R-290 at GWP 3 represents a 600-1300× climate impact reduction per kg of refrigerant.

The environmental excellence is the primary driver of R-290 adoption. Regulatory frameworks targeting climate impact (EU F-Gas, EPA AIM Act, Kigali Amendment) do not apply to hydrocarbons like R-290 — there is no phase-down schedule, no production allocation, no future end-use restriction. R-290 is structurally a long-term destination refrigerant for applications where the A3 flammability constraints can be managed.

A3 flammability — the dominant operational constraint

R-290 is ASHRAE class A3 — highly flammable [ashrae34]. The lower flammability limit (LFL) is 2.1% by volume in air; the upper flammability limit (UFL) is 9.5%. Any propane-air mixture between these concentrations will ignite if exposed to sufficient ignition energy (~0.25 mJ, easily provided by a static spark or electrical arc).

The flammability classification triggers strict equipment design constraints. IEC 60335-2-40 (heat pumps, AC) and IEC 60335-2-89 (commercial refrigeration) specify charge limits scaled to the smallest enclosed space the equipment serves, with the goal of keeping the worst-case release concentration below 50% of LFL [iec60335240][iec60335289]. Below this limit, even total refrigerant release cannot reach flammable concentration in the served space.

The 2019-2022 amendments to IEC 60335 significantly relaxed residential charge limits — from a long-standing 150g cap to up to 988g for certain configurations — by recognizing that monobloc and ductless architectures with refrigerant leak detection can safely handle larger charges. This regulatory relaxation accelerated R-290 deployment in residential heat pumps through 2023-2026.

Reading the common service temperatures for R-290

R-290 saturation values across typical service temperatures:

  • 32°F (freezing) — R-290 saturation approximately 56 PSIG.
  • 45°F (heat-pump heating) — typical winter outdoor coil temperature; R-290 saturation approximately 75 PSIG.
  • 70°F (standard reference) — R-290 saturation 110 PSIG.
  • 75°F (test reference) — R-290 saturation approximately 121 PSIG.
  • 80°F (warm-weather operation) — R-290 saturation approximately 132 PSIG.
  • 95°F (summer peak) — R-290 saturation approximately 175 PSIG.

For residential heat pumps in cooling mode at 95°F outdoor, expect roughly 70-90 PSIG suction and 200-250 PSIG discharge. For heating mode at 25°F outdoor, expect 30-50 PSIG suction and 130-180 PSIG discharge. Actual operating pressures depend on superheat, subcooling, ambient, and indoor load — comparable to R-22 across the residential envelope.

Service equipment — moderate pressures, hydrocarbon-rated handling

R-290 service equipment uses standard HVAC pressure ratings (500 PSI manifold gauges handle the moderate envelope) with hydrocarbon-specific safety and handling additions.

| Equipment / procedure | R-410A | R-290 | | --- | --- | --- | | Manifold gauge rating | 800 PSI | 500 PSI adequate | | Recovery cylinder | 600 PSI service | Hydrocarbon-rated, grounded against static | | Service port | 5/16" SAE | Application-specific (varies by OEM) | | Lubricant | POE | Mineral oil or alkylbenzene | | Compressor motor | Standard hermetic | Sealed motor per IEC 60335 | | Brazing during service | Nitrogen purge | Full recovery + nitrogen inerting; no open flames during charging | | Leak detection | Electronic A1 detector | Combustible gas detector (LEL meter) | | Charge limits | None (A1) | Per IEC 60335-2-40 or 60335-2-89 | | Vacuum target | 500 microns held 30+ min (POE hygroscopic) | 500 microns (mineral oil less hygroscopic) |

The lubricant change from R-22 era practice is minor (mineral oil for both). The flammability-specific equipment additions are significant — combustible gas detectors, hydrocarbon-rated recovery cylinders, static grounding straps during charging.

Mineral oil and alkylbenzene — back to pre-HFC chemistry

R-290 uses mineral oil or alkylbenzene lubricants — the same lubricant families used with R-22 and earlier hydrocarbon-friendly refrigerants. The non-polar hydrocarbon refrigerant and the non-polar hydrocarbon lubricant mix well and return reliably to the compressor in the refrigerant flow [ahri700].

POE oil (used with HFCs like R-410A and R-32) is NOT compatible with R-290. The polar ester groups in POE don't mix with non-polar propane, causing oil-return failures and accelerated compressor wear. Cross-contamination from residual POE in retrofit systems is a known service problem — R-22 equipment retrofitted to R-290 requires complete oil flushing to remove any HFC-era residue.

Some R-290 commercial refrigeration systems use synthetic polyolefin (PAO) lubricants for specific compressor designs that benefit from PAO's wider temperature operating range. Verify lubricant grade against equipment OEM service literature; do not assume cross-OEM compatibility.

R-290 growth in EU heat pumps — the policy and market dynamics

EU residential heat pump installation rates have grown substantially through 2020-2026 as part of the REPowerEU climate policy framework — annual installation rates roughly doubled from pre-2020 baselines. The dominant new-equipment refrigerant in this growth is R-290.

The drivers: (1) EU F-Gas Regulation 2024 revisions target sub-150-GWP refrigerants in residential heat pump categories through 2030 — R-290 at GWP 3 clears the threshold with maximum margin; (2) IEC 60335-2-40 charge limit relaxation through 2019-2022 amendments permitted larger residential R-290 systems than the legacy 150g cap; (3) monobloc heat pump architecture (outdoor-only refrigerant circuit) addresses indoor flammability concerns that limited split-system R-290 deployment.

Major EU heat pump OEMs (Vaillant aroTHERM plus, Daikin Altherma 3 R MT, Mitsubishi Ecodan R290, Bosch Compress 7400i AW, Viessmann Vitocal 250-A) shipped R-290 monobloc heat pumps extensively through 2023-2026. Market analysts expect R-290 to take majority share of new EU residential heat pump installations by 2027-2028.

US adoption is lagging EU by approximately 3-5 years. Charge limit revisions to UL 60335 are working through the standards-development process; residential US R-290 heat pump availability is currently limited to small monobloc units. Acceleration is expected through 2026-2030 as standards align with EU practice.

How to think about R-290 in 2026 and beyond

R-290 is the structurally low-GWP refrigerant for applications where the A3 charge limits can be managed through equipment design. EU residential heat pumps are the largest growth market; US adoption is expected to follow through 2026-2030 as charge limit standards converge.

For commercial refrigeration, R-290 dominates in self-contained equipment — bottle coolers, vending machines, ice makers, plug-in commercial display cases. Charge limits per IEC 60335-2-89 are workable for these applications (typically 150-500g) and the equipment design (sealed system, no field service of refrigerant) handles A3 safety naturally.

For larger commercial and industrial refrigeration, the choice between R-290 (charge-limited but lowest GWP) and R-744 CO₂ (no charge limit but higher equipment cost) depends on application scale and capital structure. R-290 fits small-to-medium installations; R-744 dominates supermarket-scale.

For service technicians, R-290 work requires hydrocarbon-specific training (charge limits, ignition-source elimination, combustible gas detection, grounded recovery procedures) on top of standard HVAC service skills. EPA Section 608 plus HC-specific OEM training is the typical certification path.

11

Frequently asked

›What is the normal operating pressure of R-290?

Moderate — lower than R-22, much lower than R-410A. At 70°F R-290 saturation is approximately 110 PSIG (CoolProp 7.2.0); at 95°F outdoor ambient, approximately 175 PSIG. Standard 500 PSI manifold gauges handle R-290's operating envelope with comfortable margin.

Operational ranges for typical applications: residential heat pump 50-200 PSIG suction depending on mode; small commercial refrigeration evaporator 15-40 PSIG suction at typical setpoints.

›How much R-290 can I use in a residential heat pump?

Depends on installation specifics. The 2022 IEC 60335-2-40 revision raised charge limits significantly above the previous 150g cap. For sealed-system residential heat pumps with appropriate safety design (low-leak components, refrigerant detection), charges up to 988g are permitted in many configurations [iec60335240].

Actual allowed charge depends on room volume, installation mounting (floor/wall/ceiling), and equipment certification. Verify against equipment OEM data plate and local code.

›What's R-290's GWP?

3 per IPCC AR5 — essentially zero compared to HFC alternatives. R-22 (1810), R-410A (2088), R-404A (3922) are 600-1300× higher GWP per kg. R-290's natural-refrigerant status places it outside any GWP-based phase-down framework [ipccar5][epasnap].

›What lubricant does R-290 use?

Mineral oil or alkylbenzene typically — compatible with hydrocarbon refrigerants. POE oil (used with HFCs) is NOT compatible with R-290. Some R-290 systems use synthetic polyolefin (PAO) lubricants for specific compressor designs.

The lubricant choice is equipment-OEM-specific. Verify against equipment service literature before adding oil to an R-290 system.

›Is R-290 the same as propane in a barbecue tank?

Same molecule, different purity. Refrigerant-grade R-290 is specified at ≥99.5% purity per AHRI 700, with controlled moisture content and limited mercaptan odorant [ahri700]. Commercial-grade propane has odorants added (ethyl mercaptan for leak detection) and may contain butane and other hydrocarbons.

Never use commercial fuel-grade propane as a refrigerant. The odorants and impurities damage compressor lubrication and produce variable thermodynamic behavior. Refrigerant-grade R-290 is sold by HVAC refrigerant distributors in dedicated cylinders.

›Why is R-290 growing in EU heat pumps?

EU F-Gas Regulation revisions (2024) target tighter HFC thresholds in residential heat pumps. R-290's GWP 3 sits well below any plausible threshold, providing structural regulatory certainty. EU heat pump OEMs (Vaillant, Daikin, Mitsubishi, Bosch, Viessmann, Stiebel Eltron) have launched R-290 monobloc air-source heat pump lines extensively through 2022-2025.

The monobloc architecture (refrigerant circuit fully contained in outdoor unit; only water plumbing into the house) eliminates the indoor flammability concern that limits R-290 use in split-system architectures.

›Is R-290 safe to handle?

Highly flammable — A3 classification (ASHRAE 34). Concentrations between 2.1% and 9.5% by volume in air will ignite if exposed to sufficient ignition energy. Service procedures must eliminate all potential ignition sources: no open flames, no electrical sparks, no static discharge during refrigerant transfer.

Equipment-installed safety controls (sealed motors, refrigerant detection with ventilation interlock, isolation valves) reduce risk to acceptable levels for normal operation. Service procedures parallel hydrocarbon storage tank service in their fire-safety discipline.

›Can I retrofit an R-22 system to R-290?

Not safely as a refrigerant-only retrofit. R-22 equipment has electrical components in the refrigerant circuit (motor windings, contactors, switches) that are potential ignition sources for R-290's flammable mixture. R-290 systems require sealed motor design and ignition-source isolation per IEC 60335.

For an R-22 system, the practical paths are continued service with reclaimed R-22 (legal indefinitely), retrofit to a mineral-oil-compatible HFC blend (R-407C, R-422D, R-438A — A1 safety preserved), or full replacement with new R-32 / R-454B equipment (A2L) or R-290 equipment (A3, more restrictive).

Download this dataset

Full PT chart for R-290 · CC BY 4.0 · attribute the source

CSV JSON
13

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]
    CoolProp 7.2.0 (Bell, Wronski, Quoilin, Lemort 2014)
    2014 (continually updated)http://www.coolprop.org/doi:10.1021/ie4033999
  4. [4]
    IEC 60335-2-40 — Particular requirements for electrical heat pumps, AC, and dehumidifiers (A3 charge limits)
    2022 revisionhttps://webstore.iec.ch/publication/61347
  5. [5]
    IEC 60335-2-89 — Particular requirements for commercial refrigerating appliances with integral or remote condensing unit (A3 charge limits)
    2019 revisionhttps://webstore.iec.ch/publication/61349
  6. [6]
    ASHRAE Standard 15-2022 — Safety Standard for Refrigeration Systems
    2022https://www.ashrae.org/technical-resources/standards-and-guidelines
  7. [7]
    EPA SNAP — R-290 acceptable for specific commercial refrigeration end-uses
    Multiple acceptability rules 2011-2019https://www.epa.gov/snap
  8. [8]
    International Institute of Refrigeration (IIR) — Natural refrigerants documentation
    https://iifiir.org/
  9. [9]
    AHRI Standard 700-2019 — Specifications for Refrigerants
    2019https://www.ahrinet.org/search-standards
  10. [10]
    NIST Chemistry WebBook — Propane thermophysical properties (CAS 74-98-6)
    https://webbook.nist.gov/chemistry/fluid/

Data sources & provenance

PT chart
CoolProp 7.2.0 Propane
Cross-checked against
CoolProp 7.2.0 (Propane); ASHRAE Handbook of Refrigeration 2022
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.