Contents - Index

Fluid Property Information


EES provides built-in thermophysical property data for the fluids listed below. The fluids are grouped into Real Fluids, Ideal Gases,  Brines, Incompressible Substances, and Mixtures.   Some of these refrigerants in the Real Fluids category, e.g., R410A,  R450A, R513A and others, are mixtures but their properties can be represented using similiar equations to those used for the pure real fluids.  Property data for air-water mixtures (psychrometrics) are provided by fluid AirH2O.  Incompressible substances are not listed as they are provided with external Lookup table files.  However, you can view a list of all incompressible substances by selecting Function Info from the Options window, clicking the Thermophysical properties button and then selecting the Incompressible option. 


Click on a fluid name to access additional information for that fluid.  All names in EES are case-insensitive.  Note that, in addition to the list of fluids shown below, the property functions will operate with any of the 1262 gases provided in the NASA ideal gas data baseAdditional fluid property data can be added by the user.   


-------------------------------------- REAL FLUIDS ------------------------------    -----------MIXTURES ----------

Acetone m-Xylene R32 Air_ha

Acetylene Methane R40 NH3H2O

Ammonia Methanol R41 R404A

Argon n-Butane R113 R407C

Benzene n-Decane R114 R410A

Butene n-Dodecane R115 R417A

Carbondioxide n-Heptane R116 R423A

Carbonmonoxide n-Hexane R123 R427A

CarbonylSulfide n-Octane R124 R448A

Cis-2-Butene n-Nonane R125 R449A

Cyclohexane n-Pentane R134a R450A

Cyclopentane n-Undecane R141b R452A

D4 Neon R142b R452B

D5 Neopentane R143a R454A

Deuterium   Nitrogen R143m R454B

DeuteriumOxide NitrousOxide R152a R454C

DiethylEther Novec649 R161 R455A

DimethylCarbonate o-Xylene R218 R460A

DimethylEther orthoHydrogen R227ea R466A

Ethane Oxygen R236ea R500

Ethanol o-Zylene R245fa R502

Ethylbenzene paraHydrogen R236fa  R507A

Ethylene Propane R290  R508B

Fluorine p-Xylene R365mfc  R513A

Helium Propylene R600 R513B

HFE7000 SES36 R600a  R514A

HFE7100 Steam R717 R515A

HFE7200 Steam_IAPWS R718 

HFO1336mzz(Z) Steam_NBS R744 

HFE7500 SulfurDioxide RC318 

Hydrogen SulfurHexafluoride R1216 

HydrogenChloride Toluene R1224yd(Z) 

HydrogenSulfide trans-2-butene R1225ye(Z) 

Ice Water R1233zd(E) 

Isobutane Xenon R1234yf 

Isobutene R11 R1234ze(E) 

Isohexane R12 R1234ze(Z) 

Isopentane R13 R1243zf 

Krypton R13I1 RE245cb2 

MDM R14 RE245fa2 

MD2M R22   .FLD files

MD4M R23  




----- IDEAL GASES -----            ------ BRINES ------                         ------ INCOMPRESSIBLE ------

Air CACL2   (Calcium Chloride-Water)                Incompressible substances are provided in

AirH2O EA  (Ethylene Alcohol-Water)                        separate Lookup (.LKT) tables.   See the

Ar EG  (Ethylene Glycol-Water)                         Function Information dialog for a

CH3OH GLYC  (Glycerol-Water)                                list of these substances.

CH4 K2CO3  (Potassium Carbonate-Water)

C2H2 KAC  (Potassium Acetate-Water)

C2H4 KFO  (Potassium Formate-Water)

C2H6 LICL  (Lithium Chloride-Water)

C2H5OH MA  (Methyl Alcohol-Water)

C3H8 MGCL2  (Magnesium Chloride-Water)

C4H10 NACL  (Sodium Chloride-Water)

C5H12 NH3W  (Ammonia-Water)

C6H14 PG  (Propylene Glycol-Water)












NASA Gases


The fluid properties are of three distinct types:  ideal gas, real fluid and brines/incompressible.  The enthalpy and internal energy of ideal gas substances are dependent only upon temperature.  EES will not accept pressure, along with temperature, as an independent property input in the Enthalpy and IntEnergy functions for ideal gas substances.  A general rule is that substances having a name that is a chemical formula, e.g.,  N2 or CO2, are implemented to be ideal gases whereas real fluids use spelled-out names, e.g., Nitrogen and CarbonDioxide.  Air and AirH2O (psychrometric relations) are exceptions to this rule in that both are based on ideal gas behavior.  Whenever a chemical symbol notation (e.g., Ar, N2, CO2, CH4 etc.) is used, the substance is modeled as an ideal gas and the enthalpy and entropy values are based on JANAF table references.  The JANAF table reference for enthalpy is based on the elements having an enthalpy value of 0 at 298K (537R).  The entropy of these substances is based on the Third Law of Thermodynamics. 


Whenever the substance name is spelled out (e.g., Argon, Steam (or Water or R718), Nitrogen, R12, CarbonDioxide, Methane, etc.) the substance is modeled as a real fluid with subcooled, saturated, and superheated phases.  Most of the real fluids in the table above employ a high accuracy equation of state that accurately provides property information at all conditions including the vicinity of the critical point and the subcooled region.  Specific references to the equation of state are provided for each fluid.  Otherwise, the fluid properties in the subcooled region are determined using the Martin-Hou equation of state (A.I.Ch.E. Journal, Vol. 1, No. 2, 1955, pp. 142-151) and by assuming the fluid is incompressible.  The Martin-Hou equation of state has a claimed accuracy of 1% in specific volume for conditions at which the density is less than 1.5 * Critical density.   Thermodynamic properties at densities greater than 1.5 * critical density or in the vicinity of the critical point may be inaccurate with the Martin-Hou equation of state.


Brine properties are provided given the temperature and mass concentration in %.  


NH3H2O (ammonia-water) is a mixture.  It requires 3 independent properties. The property designators are the same as for pure fluids with the following two differences.  X designates mass fraction.  Q designates quality.


Starting with version 10.364, the property keywords Water, Steam, R718 and Steam_IAPWS are treated identically.  All four keywords provided access to property correlations use the Steam_IAPWS property correlations, which provide the most accurate property data for water substance and it is the current international standard.  Steam_NBS and Ice use the property correlations published by Harr, Gallagher, and Kell (Hemisphere, 1984).These property correlations were the basis of the international standard for water before 1995.


Starting with version 10.627, EES can read .FDL files used with the NIST REFPROP program, which extends the number of pure fluids for which EES can provide property information.