HVAC Toolkit
R290

R-290 Propane Refrigerant

Natural Refrigerant - Ultra-Low GWP Alternative

GWP
3
Safety Class
A3
Type
Natural
ODP
0
Formula
C₃H₈

A3 Flammable Refrigerant

R-290 is highly flammable. Special training, equipment, and safety protocols are required. Only use in equipment designed for R-290.

Overview

R-290 (Propane) is a natural hydrocarbon refrigerant with an ultra-low Global Warming Potential of just 3—making it one of the most environmentally friendly refrigerants available. It's increasingly used in small self-contained systems like refrigerators, vending machines, and small heat pumps.

While R-290 offers excellent thermodynamic properties and environmental benefits, its A3 flammability classification requires special equipment design, charge limits, and technician training.

Market Trend: By 2030, R-290 is expected to become the standard for hermetically sealed systems and small capacity heat pumps, driven by EU F-Gas regulations and global HFC phase-down commitments.

Technical Properties

Chemical Name Propane
Chemical Formula C₃H₈
Molecular Weight 44.1 g/mol
Boiling Point (1 atm) -42.1°C / -43.8°F
Critical Temperature 96.7°C / 206°F
Critical Pressure 4.25 MPa / 617 psia
GWP (100 year) 3
ODP 0
Safety Classification A3 (Flammable)
Lower Flammability Limit 2.1% vol
Upper Flammability Limit 9.5% vol
Lubricant MO, AB, POE

GWP Comparison

R-290's ultra-low GWP makes it one of the most climate-friendly refrigerants:

R-290
3
R-454B
466
R-32
675
R-410A
2088

R-290 has 99.9% lower GWP than R-410A

Pressure-Temperature Chart

Full Chart →
°C °F psig kPa bar
-30 -22 5.4 128 1.28
-20 -4 16.8 205 2.05
-10 14 31.8 310 3.10
0 32 51.0 447 4.47
10 50 75.1 620 6.20
20 68 104.8 834 8.34
30 86 140.7 1,094 10.94
40 104 183.9 1,407 14.07
50 122 235.0 1,779 17.79

Charge Limits

Due to flammability concerns, R-290 charge amounts are limited based on application and room size:

Application Max Charge Standard
Domestic Refrigerators 150g (5.3 oz) IEC 60335-2-24
Self-contained Commercial 150g (5.3 oz) UL 471A
Room AC (USA, 2024+) 500g (17.6 oz) UL 484
Portable AC 300g (10.6 oz) IEC 60335-2-40

A3 Safety Requirements

  • No ignition sources during service
  • Adequate ventilation required
  • Use explosion-proof recovery equipment
  • HC-rated leak detectors only
  • Never use in non-HC equipment
  • Specialized training required

Applications

  • Domestic Refrigerators
  • Chest Freezers
  • Vending Machines
  • Display Coolers
  • Small Heat Pumps
  • Dehumidifiers

Advantages

  • Ultra-low GWP (3)
  • Excellent energy efficiency
  • Low cost and readily available
  • Compatible with common oils
  • Zero ozone depletion
  • Future-proof (no phase-out)

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