Thermodynamic Properties of R744 (Carbon Dioxide - CO 2 )

Critical Pressure: 7.377 MPa, Critical Temperature 30.978°C
Ideal Gas Constant of Carbon Dioxide: R = 0.1889 kJ/kg.K

CO 2 Property Tables:

• Saturation Properties - Temperature Table (-20°C - 5°C)

• Saturation Properties - Temperature Table (5°C - 30.978°C)

• Saturation Properties - Pressure Table (2 MPa - 5 MPa)

• Saturation Properties - Pressure Table (5 MPa - 7.377 MPa)

• Superheated Vapor Properties - (2.0 MPa - 7.0 MPa)

• Transcritical Vapor Properties - (8.0 MPa - 13.0 MPa)

• Transcritical Vapor Properties - (14.0 MPa - 20.0 MPa)

CO2 Property Tables (Excel Version)

• Saturation Properties - Temperature Table

• Saturation Properties - Pressure Table

• Superheated and Transcritical Vapor Properties

Source of data: NIST Chemistry WebBook - accessed March 2007

CO 2 Property Diagrams:

• Pressure-Enthalpy ( P-h ) Diagram

• Enthalpy-Entropy ( h-s ) Diagram

Note : The current refrigerant R134a has a Global Warming Potential (GWP) of 1300 with respect to CO 2 . There is currently serious consideration of replacing it with R744 (Carbon Dioxide) in refrigeration and heat pump applications, as well as automotive air conditionong systems..

A typical home heat pump system is shown below, followed by the P-h plot. Notice how the transcritical cycle conveniently allows hot water heating together with space heating and air conditioning.

Engineering Thermodynamics by Israel Urieli is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License