This Python module (available for both python version 2.7 and 3.2) uses a compiled fortran version of the NIST Standard Reference Database 23 (a.k.a. REFPROP (REFerence fluid PROPerties)), version 9.0.

REFPROP source code is copyright the United States Secretary of Commerce and its distribution is controlled by the National Institute of Standards and Technology (NIST). You may ask, why is something produced by the United States government copyrighted from the people of the United States? In 1968 the United States Congress passed "The Standard Reference Data Act" which authorized the United States Secretary of Commerce to withold copyrights from the people of the United States. More information about this law can be found at: http://www.nist.gov/srd/publiclaw.cfm . If you are a United States citizen and find this law inappropriate, contact your Senators (http://www.senate.gov/contacting/index_by_state.cfm) and Congressman (http://www.house.gov/representatives/) and voice your oppinion!

In order to legally obtain a copy of the REFPROP software and fortran source codes, use the following web page: http://www.nist.gov/srd/nist23.cfm . Once purchased, the software will be delivered as a windows self extracting installation file (.exe). In order to access the files required by this python module, you must install REFPROP using this self extracting installation file and install REFPROP in windows.

FOR WINDOWS:
Install the REFPROP software on your system.
Add two environment variables called RPprefix and Path. See http://www.boulder.nist.gov/div838/theory/refprop/Frequently_asked_questions.htm at Excel Applications for more details.
Install the python API to refprop in your python dist-packages

FOR LINUX:
Use WINE to install refprop.exe into the C:\Program Files\REFPROP\ directory
OR use a virtual machine with windows to install REFPROP (if WINE doesn't work for you) and then make the installed files available on a linux accessible partition.
Execute the shell script, rp2so, to compile and link the refprop shared object files. In order for rp2so to run successfully, you will need to have the following installed on Linux:
	gfortran
	sed
	dos2unix
Install the python API to refprop into your python dist-packages folder