Contents - Index



EES provides properties for many pure fluids and a few mixtures such as R407C, R410A, and ammonia-water. Click here to view a list of the fluids for which property data are built into EES. The National Institute of Standards and Technology (NIST) has developed REFPROP (also called NIST Standard Reference Database 23), which provides high accuracy property data for pure refrigerants and refrigerant mixtures. REFPROP is the most authoritative source of pure fluid property data.  REFPROP also provides high accuracy data for refrigerant mixtures, ammonia-water, and most mixtures of organic fluids. 


The EES_REFPROP is an optional interface has been developed for REFPROP (versions 8 and newer) that allows the NIST property data base to be used with the equation-solving and other features of EES. The EES_REFPROP manual provides a detailed description of the EES calls needed to access the REFPROP data.  The $ConvertEESREFPROPUnits directive provides automatic unit conversion of the inputs to and outputs from the EES_REFPROP interface.  If you are involved in modeling refrigeration systems that use property information not included in EES, you will find the NIST REFPROP program and the EES_REFPROP interface to be of considerable interest. 


The EES_REFPROP interface uses the default reference state within REFPROP for the values of specific enthalpy and entropy.  Howeverk the reference state can be changed with the $REFERENCE directive.


Both the NIST REFPROP program and the EES_REFPROP interface are required to allow EES to access property data from REFPROP. REFPROP can be ordered from NIST.  The EES_REFPROP interface can be ordered from the F-Chart website.  Note that the EES_REFPROP interface is paired to an EES license and it will only operate with that license. The number of users for the EES_REFPROP interface must match the number of users for the EES license. The standard EES_REFPROP interface is a 32-bit dynamic link library (DLL) that interfaces with the 32-bit REFPROP program. A 64-bit version of EES is available and it requires 64-bit DLLs, including the 64-bit EES_REFPROP interface.


Note that EES can use REFPROP .FDL files directly to provide property data for pure fluids without use of the EES_REFPROP interface. However, this method can not be used for mixtures.


See also: Using REFPROP .FDL files