NIST NSRDS 73-2020

REFLEAK:

NIST Leak/Recharge Simulation Model 

for Refrigerant Blends

Version 6.0

User’s Guide

J. Steven Brown

Piotr A. Domanski

Riccardo Brignoli

Young Jin Yoon

This publication is available free of charge from:

http://dx.doi.org/10.6028/NIST.NSRDS.73-2020
NIST NSRDS 73-2020

REFLEAK:

NIST Leak/Recharge Simulation Model 

for Refrigerant Blends

Version 6.0

User’s Guide

J. Steven Brown

The Catholic University of America

Piotr A. Domanski

Engineering Laboratory

Riccardo Brignoli

Engineering Laboratory

Young Jin Yoon

Engineering Laboratory

This publication is available free of charge from:

http://dx.doi.org/10.6028/NIST.NSRDS.73-2020

May 2020

U.S. Department of Commerce 

Wilbur L. Ross Jr., Secretary

National Institute of Standards and Technology 

Walter Copan, Under Secretary of Commerce for Standards and Technology and Director 
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The National Institute of Standards and Technology (NIST), uses its best efforts to deliver a high-quality 

copy of the Database and to verify that the data contained therein have been selected on the basis of 

sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be 

liable for any damage that may result from errors or omissions in the Database.

(c) 1998, 1999, 2002, 2007, 2009, 2011, 2016, 2017, 2020 copyright by the U.S. Secretary of Commerce 

on behalf of the United States of America. All rights reserved. No part of this database may be 

reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, 

mechanical, photocopying, recording, or otherwise, without the prior written permission of the distributor.

Certain trade names and company products are mentioned in the text to specify adequately the computer 

products and equipment needed to use this software. In no case does such identification imply 

endorsement by the National Institute of Standards and Technology of these computer products and 

equipment, nor does it imply that the products are necessarily the best available for the purpose.

Microsoft is a registered trademark, and Windows is a trademark of Microsoft® Corporation. All other 

brand and product names are trademarks or registered trademarks of their respective companies.
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ACKNOWLEDGMENTS

We acknowledge Dr. David Didion and Dr. Min Soo Kim for developing earlier versions of this simulation 

model; and Drs. Eric W. Lemmon, Mark O. McLinden, Marcia L. Huber, and Ian H. Bell for their work with 

REFPROP upon which this simulation model is based. Dr. Riccardo Brignoli of VIS Engineering, Italy,

and Dr. Young Jin Yoon of LG Electronics, South Korea, co-authors of this version of REFLEAK, made 

their contributions during their tenure at NIST Engineering Laboratory as visiting research associates.
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CONTENTS

1. INTRODUCTION................................................................................................................................. 1

2. INSTALLATION................................................................................................................................... 2

3. MODELING OF LEAK AND RECHARGE PROCESS......................................................................... 2

4. DESCRIPTION OF THE SIMULATION MODEL................................................................................. 3

REFERENCES........................................................................................................................................ 4

Appendix A. EXAMPLE RUN FOR LEAK PROCESS ............................................................................ 5

Appendix B. EXAMPLE RUN FOR LEAK AND RECHARGE PROCESS............................................. 13

Appendix C. ICONS.............................................................................................................................. 15

Appendix D. SINGLE-COMPOUND FLUIDS AVAILABLE IN REFLEAK ............................................. 16

Appendix E. PREDEFINED REFRIGERANT BLENDS AVAILABLE IN REFLEAK ............................. 18

Appendix F. CALCULATION OF INITIAL VOLUMETRIC QUALITY BASED ON FRACTION

 OF MAXIMUM LIQUID FILL ............................................................................................ 21

Appendix G. CONTACTS .................................................................................................................... 22
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1. INTRODUCTION

As alternatives to refrigerants with a high global warming potential (GWP), blends of two or more 

refrigerants are being utilized as working fluids in heat-pump, air-conditioning, and refrigeration systems, 

and in organic Rankine cycles. Generally, these blends form zeotropes, which show temperature and 

composition changes during evaporation, condensation, and flashing processes whether they are 

intended (i.e., through an expansion device) or unintended (e.g., a leak from a container or system). For 

zeotropic blends, it may be important and necessary to predict the composition change for any of these 

events. 

REFLEAK simulates leak and recharge processes for zeotropic refrigerant blends. This Windows-based 

simulation model provides an easy-to-use package that allows estimation of composition changes of 

zeotropic blends in leak and recharge processes for either vapor or liquid leaks under isothermal or 

adiabatic conditions. The generic model of these processes used in REFLEAK and example simulation 

studies are presented in [1, 2]. Other computer simulations and laboratory leak measurements of specific 

blends are reported in [3, 4].

Thermodynamic properties of the refrigerant blends are calculated using the NIST Standard Reference 

Database 23: Reference Fluid Thermodynamic and Transport Properties – REFPROP, Version 10.0 [5].

Uncertainties in Calculated Properties

The objective in selecting fluid property models for use in REFPROP was to implement the most accurate 

models currently available. The user should be aware that the uncertainties in these models vary 

considerably depending on the fluid, property, and thermodynamic state. It is thus impossible to give a 

simple, global statement of uncertainties. Even for the most-studied fluids with equations of state based 

on accurate, wide-ranging data, uncertainties are complicated functions of temperature and pressure. 

The interested user is referred to REFPROP’s original literature sources for details. 

The user is further cautioned that, by the very nature of computational results, property data are often 

displayed with more digits than can be justified based on the accuracy of the property models or the 

uncertainties in the experimental data to which the models were fitted.

Remarks

Occasionally a convergence problem may occur in calculating thermodynamic properties of some 

azeotropic or near-azeotropic blends, which will result in an error message. Since this will typically occur 

only for a narrow band of input conditions, the user may want to change the initial input conditions and 

try the analysis again, or perhaps the property values obtained on either side of the error zone can be 

interpolated to meet the user’s needs. 

The simulation model provides 'Help' sections with several keywords to assist the user. 

NIST regularly updates the REFPROP database [5]. When this occurs, REFLEAK will be revised to 

reflect the new property routines. 

Compared to version 4.0, version 5.0 of REFLEAK included a Graphical User Interface (GUI) built on 

the .NET platform of Microsoft® and extended to 10 the number of refrigerants allowed in a blend. This 

version 6.0 migrates REFLEAK from REFPROP 9.1 to REFPROP 10.0 for the representation of 

thermophysical properties. This transition expands the list of refrigerants to those available in REFPROP 

10.0, including new low-GWP fluids (Appendix D).
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2. INSTALLATION

System Requirements

- Personal computer capable of running Microsoft Windows 7, 8, 10 with Microsoft .NET Framework 

version 4.7.2 or later and Microsoft Visual C++ Runtime Library (for x86) version 14 or later.

- A hard disk with 17 megabytes of available space. The installation process will require additional 

104 MB of space for Microsoft .NET Framework version 4.7.2 and Microsoft Visual C++ Runtime 

Library (for x86) version 14 if they are not installed already.

- The screen resolution should be set to 1024 x 768 or higher to view images in their entirety. 

Installation Procedure 

Execute the REFLEAK installation file setup.exe with REFLEAK 6.0 Installer.msi residing in the same 

directory. Follow the on-screen instructions. To run the program, click on the REFLEAK icon on the Start 

Menu.

3. MODELING OF LEAK AND RECHARGE PROCESS

During a leak process of a refrigerant zeotropic blend, fluid in a vapor or liquid phase escapes from the 

system, where preferential evaporation of one or more components makes the composition in the vapor 

phase different from that in the liquid phase. 

Inherently, the temperature of the fluid in the system decreases since the energy required for vaporization 

is removed from the refrigerant remaining in the system and from the system material. 

Two idealized cases are considered in the simulation model: (1) isothermal leaks and (2) adiabatic leaks. 

An isothermal leak process represents a very slow leak situation, in which the temperature of the system 

remains constant because of the heat transfer through the walls from the environment. In an adiabatic 

leak process, it is assumed that the refrigerant leaks so quickly that no heat is transferred through the 

walls, and thus the temperature in the system decreases as the leak progresses. A comparison of 

experimental data with REFLEAK simulations has shown that slow leaks are well predicted by the 

isothermal assumption. However, all real systems have non-negligible heat capacity, which will release 

some thermal energy during the expanding vaporization process as the liquid temperature drops. Thus, 

an actual fast leak process probably falls somewhere between the adiabatic and isothermal assumptions. 

In order to model these leak situations, the following assumptions are made:

(1) During the leak, only one phase (vapor or liquid) is escaping from the system.

(2) The refrigerant blend inside the system is at a vapor-liquid equilibrium state.

(3) The leak process is either isothermal or adiabatic.

(4) The escaping refrigerant has the same composition as the vapor inside the system during a vapor 

leak, and the same composition as the liquid during a liquid leak. 

In the recharging process, a leak of a portion of the system charge is simulated, and then the system is 

recharged with a refrigerant of the original composition. The recharged mass is equal to that which has

leaked from the system. After recharging during an adiabatic leak process, the temperature in the system 

is "reset" to the initial temperature.

The leak process is simulated in a quasi-steady manner by alternate steps of refrigerant escaping and 

adjustment of the remaining refrigerant to thermodynamic equilibrium. The thermodynamic properties 

are calculated using the property routines included in the NIST Reference Fluid Thermodynamic and 

Transport Properties Database (REFPROP): Version 10.0 [5]. Therefore, all limitations applicable to 

REFPROP (e.g., avoiding the region near the critical point) are applicable to REFLEAK. 
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4. DESCRIPTION OF THE SIMULATION MODEL

The leak/recharge simulation model consists of three sections: (1) a pre-processing section to input 

required data, (2) a main section to simulate the leak/recharge process, and (3) a post-processing section 

to display calculated results, and save and/or print graphs. 

After initiating the simulation model, a user can take the following actions:

(1) Select the refrigerant blend for the leak/recharge simulation. Note that the refrigerant blend must 

be chosen before any other data can be input or action taken, except that of changing units. 

a. For a predefined blend, press the appropriately labeled command button.

b. For a user-defined blend, press the appropriately labeled command button.

i. Select up to ten components from the list box.

ii. Specify the mass (or mole) fractions for each component; in either case, they must sum 

to one.

iii. If desired, the user-defined blend can be stored for later retrieval as a predefined blend.

(2) Choose the simulation mode: leak only or leak/recharge.

(3) Choose the type of leak: isothermal or adiabatic.

(4) Choose the leaking phase: vapor or liquid.

(5) Choose SI or IP (Inch-Pound) units.

(6) Input the initial leak condition by specifying:

a. Initial refrigerant temperature.

b. Initial vapor volumetric quality.

Optionally, the initial vapor volumetric quality at the leak initial temperature can be calculated 

from a fraction of the maximum liquid fill at a given fill temperature. This option follows the 

specification of the initial volumetric quality used in ANSI/ASHRAE Standard 34 [6].

Appendix F of this report outlines the calculation procedure used by REFLEAK. Note that if 

this option is chosen, the user must press the ‘Calculate’ command button before the 

‘Analyze’ command button will be highlighted and a simulation can proceed. 

(7) Input the number of recharge cycles when simulating the leak/recharge process.

(8) Input the mass percentage loss for recharging the system when simulating the leak/recharge 

process.

After the input data have been specified, click the 'Analyze' command button. After the analysis has 

been completed, a plot window will appear displaying the simulation results. 

In the post-processing section, the following functions are provided:

(1) Display of the calculated results in graphical format (Figures A-14 and B-2); the graph shows 

mass compositions of the liquid and vapor phases as a function of the leaked mass. A vertical 

blue line in the graph indicates the specific location on the x-axis (leaked mass (%)) for which 

mass compositions are displayed. The location of the vertical bar can be changed to a specific 

value of the leaked mass (%) via the slider bar located in the lower right corner of the screen. 

Data at this specific value of leaked mass is displayed in the lower part of the graph for 

temperature, pressure, volumetric quality (void fraction), liquid specific volume, and vapor 

specific volume. In lieu of compositions of the liquid and vapor phases being plotted along the yaxis, temperature or pressure can be plotted instead using the ‘Option’ command button and 

then by using the ‘Y Data’ frame.

(2) The ‘Option’ command button can also be used to change the limits of the y-axis by using the ‘yAxis Limits’ frame.

(3) Print the graph with data.

(4) Redraw the graph.

(5) Save numerical simulation results.

(5) Close the display of data and graph.

The input data can be stored to a file using the ‘Save’ or ‘Save as’ command from the File menu. The 

file with data is saved to C:\Users\ xxx\Documents\REFLEAK data, where ‘xxx’ is the user name on a 

given computer, unless the user selects a different location.
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After a simulation has been completed, another simulation can be executed from the main window. The 

subsequent simulation can be performed by inputting, if so desired, a different refrigerant blend and/or 

different initial conditions, both by repeating the several steps described earlier in this section. If a user 

selects 'New' from the 'File' menu, all the input data are set to the default values. Note that if the user 

modifies any of the data after a simulation has been run, the previous simulation results will be removed 

from memory.

REFERENCES

[1] Kim, M.S., Didion, D.A., 1995. Simulation of Isothermal and Adiabatic Leak Processes of Zeotropic 

Refrigerant Mixtures, Int. Journal of HVAC&R Research, ASHRAE, Atlanta, Georgia, 1(3), 3-20.

[2] Kim, M.S., Didion, D.A., 1995. Simulation of a Leak/Recharge Process of Refrigerant Mixtures, Int. 

Journal of HVAC&R Research, ASHRAE, Atlanta, Georgia, 1(3), 242-254.

[3] Shiflett, M.B., Yokozeki, A., Reed, P.R., 1992. Property and Performance Evaluation of 'SUVA' HP 

Refrigerants as R-502 Alternatives, Proc. of 1992 Int. Refrigeration Conference, Purdue Univ., West 

Lafayette, Indiana, 1, 15-22. 

[4] Kruse, H., Rinne, F., 1992. Performance and Leakage Investigations of Refrigeration and AirConditioning Systems Using Refrigerant Mixtures as Working Fluids, Proc. of 1992 Int. Refrigeration 

Conference, Purdue Univ., West Lafayette, Indiana, 2, 621-630. 

[5] Lemmon, E. W., Bell, I.H., Huber, M. L., McLinden, M. O., 2018. NIST Standard Reference Database 

23: Reference Fluid Thermodynamic and Transport Properties – REFPROP, Version 10.0, National 

Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Maryland, 

U.S.A.

[6] American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., (ASHRAE), 2016.

ANSI/ASHRAE Standard 34-2016, Designation and Safety Classification of Refrigerants.

[7] McLinden, M.O., 2007, Private communication. 
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Appendix A

EXAMPLE RUN FOR LEAK PROCESS

A sample execution of the leak/recharge simulation model for a leak process is described below. In this 

example, a leak process for an R32/134a blend with a composition of 30/70 mass percentage is 

simulated. The leak process is assumed to be isothermal, and the leaking refrigerant is vapor. The initial 

temperature is 25 C, and the initial volumetric quality, which is the ratio of the volume of vapor to the 

total volume, is 0.30. 

To start the simulation model double click the REFLEAK icon. An introductory screen appears.

Figure A-1. Introductory screen

The main input screen is then displayed (Figure A-2). The first required action is to select the refrigerant. 

For this example, click the command button ‘Define New Blend’, after which Figure A-3 will appear. 

Figure A-2. Main window for data entry
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Figure A-3. Window for selecting components for a user-defined blend

For this particular example, first select R32 from the list on the left and click ‘Add’, and then repeat this 

action for R134a. After doing so, the window will appear as shown in Figure A-4. Note: to remove a 

refrigerant from the blend, select the refrigerant from the list on the right (see Figure A-4) and click 

‘Remove’. Once the desired refrigerants have been chosen, click ‘OK’ to proceed to the window shown 

in Figure A-5. Otherwise, click ‘Cancel’ and the window shown in Figure A-2 will reappear.

Figure A-4. Appearance of window after selection of refrigerants
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Figure A-5. Window for specifying blend composition

The specified blend can be stored as a predefined blend by clicking the command button ‘Store’, 

after which Figure A-6 will appear. To proceed with the chosen data, click the command button ‘OK’, 

after which Figure A-7 will appear. Otherwise, to annul the selection and return to the original window 

shown in Figure A-2, click the command button ‘Cancel’.

Figure A-6. Storing the user-defined blend for later use as a predefined blend

The main data entry window (Figure A-7) now provides basic information for the blend, and in addition 

to the previously enabled command buttons ‘Units’ and ‘Exit’, the command buttons ‘View Mixing 

Parameters’ and ‘Analyze’ are enabled. Also, the checkboxes ‘Vapor’ and ‘Liquid’ are enabled. By 

alternately clicking one or both of the checkboxes ‘Vapor’ and/or ‘Liquid,’ that particular phase will be 

displayed on the output graph during the post-processing stage.

A simulation can now be initiated using the default initial values by clicking the command button ‘Analyze’. 

If one desires to modify the default initial values, click the tab ‘Leak/Recharge Processes’, after which 

Figure A-8 will appear.
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Figure A-7. Main data entry window after specification of blend

Figure A-8. Main data entry window with default selections for leak/recharge Processes

The default values are 25.0 C for the initial temperature and 0.2 for the initial vapor volumetric quality. 

Moreover, the default selections are for an isothermal leak process where the leaking refrigerant is vapor. 

To modify these selections, click the appropriate radio button, or modify the desired value in the 

appropriate data boxes. To continue with this example, place the cursor in the ‘Initial Volumetric Quality’ 
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data box, and enter the value 0.30. If one were to err while typing the input data, a message such as the 

one shown in Figure A-9 will appear.

Figure A-9. Sample error message resulting from the mistyping of input data

Alternately, to implement the optional calculation procedure for initial volumetric quality, click either the 

‘Fill Temperature’ data box or the ‘Fraction of Max. Liquid Fill’ data box and enter the values, which will 

enable the ‘Calculate’ command button (Figure A-10). For this example, the fill temperature was 54.4 C, 

and the value for fraction of maximum liquid fill that results in the initial volumetric quality of 0.30 is 

entered. Once the command button ‘Calculate’ has been clicked, the window shown in Figure A-11 will 

appear. Now, the ‘Analyze’ command button is enabled. To once again specify the initial volumetric 

quality, place the cursor in the ‘Initial Volumetric Quality’ data box. In either case, once data for ‘Initial 

Temperature’ and ‘Initial Volumetric Quality’ are specified, the ‘Analyze’ command button is enabled. 
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Figure A-10. Input data for optional calculation of initial volumetric quality

Figure A-11. Input data after ‘Calculate’ command button has been clicked

From the main window for data entry (Figure A-2), the user can display the window “Mixing 

Parameters” (Figure A-12) to view and modify the selection of the mixing rule and blend parameters 

used by REFPROP to calculate the thermodynamic properties. The window includes the short-hand 

name of the mixing rule, the numerical values for the parameters associated with that rule, and 
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reference information. The blend model is based on pairs of components. For multicomponent blends, 

each binary pair is viewed separately. 

Note that changing the mixing rules and mixing parameters is not intended for a non-expert user. The 

mixing rule and values of mixing parameters displayed in the window – if they have not been altered by 

the user – are the recommended ones. Great care must be exercised in altering these choices. If the 

values are modified and the ‘Apply’ command button is clicked, a note “User defined” will be displayed 

for this particular refrigerant pair.

Figure A-12. Window for viewing and changing blend mixing models and parameters

To change the units, click the command button 'Units' on the main window for data entry (Figure A-2), 

after which Figure A-13 will appear.

Figure A-13. Selection of units 

Click the command button 'Analyze' in the main window to start the simulation.

After the simulation is completed, a graph (Figure A-14) is displayed showing composition change during 

the leak or recharge process versus mass percentage leaked out of the system. The vertical bar in the 
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graph indicates the corresponding mass fraction of each of the components. Corresponding vapor and 

liquid compositions are displayed on the screen as numbers. The vertical bar can be moved by scrolling 

the slider located on the lower right. At each mass percentage (x variable), vapor and liquid compositions 

including temperature, pressure, quality, liquid specific volume, and vapor specific volume are displayed. 

Figure A-14. Data display in a graph format (leak process)

To change the options for data display, click the command button 'Option', after which the window shown 

in Figure A-15 will appear.

Figure A-15. Options for data display

The data can be printed in graphical format by clicking the command button 'Print', selecting the menu 

item ‘File/Print’, or clicking the toolbar icon . . The numerical results can be saved in a commaseparated values (CSV) file by clicking the ‘SaveResults’ button.

When the command button 'Redraw' is clicked, the graph is redrawn on the screen. 

Clicking the command button 'Close' reloads the main window.
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Appendix B

EXAMPLE RUN FOR LEAK AND RECHARGE PROCESS

This section describes an example of a leak and recharge process for the R134a/1234yf blend simulated 

with the initial composition of 60/40 mass percentage. The leak process is assumed to be isothermal, 

and the leaking refrigerant is vapor. It is also assumed that the system is recharged when 30 % of the 

initial mass has leaked out of the system, and that the system is recharged three times with the initial 

refrigerant composition. Each time, the initial leak temperature is 20 C, and the initial volumetric quality 

is 0.20.

Double click the REFLEAK icon.

An introductory screen appears (See Figure A-1).

Follow the steps shown in Appendix A to select the refrigerant. Click the tab ‘Leak/Recharge 

Processes’ following the steps in Appendix A. Click the radio button ‘Leak and Recharge Process’. 

Input 3 into the ‘Number of recharges’ data box and input 30 in the ‘Percent mass loss for recharging’ 

data box, as shown in Figure B-1.

In the next step enter the initial leak temperature to be 20 C and the initial volumetric quality to be 

0.20. 

Figure B-1. Data entry window for the leak and recharge simulation example of this Appendix

Click the command button ‘Analyze' to start the simulation. After the simulation, the output is displayed 

in graphical format as shown in Figure B-2. 
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Figure B-2. Data display in graphical format (leak and recharge process)

The user can reproduce this run using the example file R134a-1234yf (60-40) leak-recharge.xml. This 

file can be loaded by selecting the menu item ‘File/Open' or by clicking the toolbar icon and 

selecting the “Examples” folder (Figure B-3).

Figure B-3. Example run files 
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Appendix C

ICONS

The icons in the tool bar provide additional flexibility and convenience in using REFLEAK. Individual 

functions and their equivalent menu options are listed below.

Icon Equivalent File Option Functions and Uses

New Begin a new analysis

Open Open previous analysis

Save Save the analysis

Print Print results

Analyze Run simulation

Help Open help file
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Appendix D

SINGLE-COMPOUND FLUIDS AVAILABLE IN REFLEAK

Short Name Full Chemical Name Tcrit Tcrit

 (C) (F)

R-11 trichlorofluoromethane 198.0 388.3 

R-12 dichlorodifluoromethane 112.0 233.6

R-13 chlorotrifluoromethane 29.2 84.6

R-13I1 trifluoroiodomethane 123.3 253.9

R-14 tetrafluoromethane -45.6 -50.2

R-21 dichlorofluoromethane 178.3 353.0

R-22 chlorodifluoromethane 96.2 205.1

R-23 trifluoromethane 25.9 78.7

R-32 difluoromethane 78.1 172.6

R-40 methyl chloride 143.2 289.7

R-41 fluoromethane 44.1 111.4

R-50 methane -116.7 -82.7 

R-113 1,1,2–trichloro–1,2,2–trifluoroethane 214.1 417.3 

R-114 1,2–dichloro–1,1,2,2–tetrafluoroethane 145.7 294.2 

R-115 chloropentafluoroethane 80.0 175.9

R-116 hexafluoroethane 19.9 67.8

R-123 1,1–dichloro–2,2,2–trifluoroethane 183.7 362.6

R-124 1–chloro–1,2,2,2–tetrafluoroethane 122.3 252.1 

R-125 pentafluoroethane 66.2 151.1

R-134a 1,1,1,2–tetrafluoroethane 101.1 213.9 

R-141b 1,1–dichloro–1–fluoroethane 204.2 399.6

R-142b 1–chloro–1,1–difluoroethane 137.1 278.8

R-143a 1,1,1–trifluoroethane 72.9 163.2 

R-152a 1,1-difluoroethane 113.3 235.9

R-161 fluoroethane 102.2 215.9

R-170 ethane 32.2 89.9

R-218 octafluoropropane 161.5 72.0

R-227ea 1,1,1,2,3,3,3–heptafluoropropane 102.8 217.0

R-236ea 1,1,1,2,3,3–hexafluoropropane 139.3 282.7

R-236fa 1,1,1,3,3,3–hexafluoropropane 124.9 256.9

R-245ca 1,1,2,2,3–pentafluoropropane 174.4 346.0

R-245fa 1,1,1,3,3–pentafluoropropane 154.1 309.3

R-365mfc 1,1,1,3,3-pentafluorobutane 186.9 368.3

R-290 propane 96.7 206.1

R-C318 octafluorocyclobutane 115.2 239.4

R-600 butane 152.0 305.6

R-600a isobutane or 2–methylpropane 134.7 274.5

R-717 ammonia 132.3 270.1

R-744 carbon dioxide 31.1 87.9

R-1150 ethylene 9.2 48.6

R-1216 hexafluoropropene 85.8 186.4

R-1233zd(E) 1-chloro-3,3,3-trifluoroprop-1-ene 166.5 330.1

R-1234yf 2,3,3,3-tetrafluoroprop-1-ene 94.7 202.5

R-1234ze(E) trans-1,3,3,3-tetrafluoropropene 109.4 228.9

R-1234ze(Z) cis-1,3,3,3-tetrafluoropropene 150.1 302.2

R-1243zf 3,3,3-trifluoropropene 103.8 218.8

R-1270 propylene or propene 92.4 198.4

RE-143a methyl-trifluoromethyl-ether 104.8 220.6

RE-170 dimethylether or ethylene oxide 127.2 260.9
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Short Name Full Chemical Name Tcrit Tcrit

 (C) (F)

RE-245cb2 methyl-pentafluoroethyl-ether 133.7 272.6

RE-245fa2 2,2,2-trifluoroethyl-difluoromethyl-ether 171.7 341.1

RE-347mcc 1,1,1,2,2,3,3-Heptafluoro-3-methoxypropane 164.6 328.2

CH3CH2CH=CH2 1-butene 146.1 295.1

Cyclo-C3H6 cyclopropane 125.2 257.3

C2H6O ethanol or ethyl alcohol 240.8 465.4

CH(CH3)3 isobutene or 2-methyl-1-propene 144.9 292.9

(CH3)2CH(CH2)2CH3 isohexane or 2-methylpentane 224.6 436.2

(CH3)2CHCH2CH3 isopentane or 2-methylbutane 187.2 369.0

CH3OH methanol 239.5 463.0

CH3-3(CH2)-CH3 pentane 196.6 385.8

C3H6O acetone 235.0 454.9

C4H8 cis-butene or cis-2-butene 162.6 324.7

C4H8 trans-butene or trans-2-butene 155.5 311.8

C5F12 perfluoropentane or dodecafluoropentane 147.4 297.3

C5H12 neopentane or 2,2-dimethylpropane 160.6 321.1

C6H6 benzene 288.9 552.0

C6H12 cyclohexane 280.5 536.9

C6H14 hexane 234.7 454.4

C7H16 heptane 267.0 512.6

C12H26 dodecane 385.0 724.9

SF6 sulfur hexafluoride 45.6 114.0

The user can add a new fluid to REFLEAK by placing a new fluid file into two ‘fluids’ folders. The fluid file 

must be compatible with REFPROP 10.0, and its name must start with “R” or “r” (e.g., Rnew2.fld or 

r754.fld will be recognized by REFLEAK as fluid files).

The two ‘fluids’ folders containing REFPROP fluid files are located at the following locations:

- REFLEAK main folder in which the REFLEAK.exe has been installed. The default locations is: 

 C:\Program Files (x86)\NIST\REFLEAK 6.0\FLUIDS

- C:\Users\xxx\AppData\Local\REFLEAK\REFLEAK 6.0\1.0.0.0\FLUIDS

where ‘xxx’ is the user name on a given computer. This path may be hidden according to the 

Windows setting. To get the path visible, on ‘Windows Search’ type ’Folder Options’, open the 

‘Folder Options’ window, select the ‘View’ tab; under ‘Hidden files and folders’ check 'Show 

hidden files, folders and drives'. 
18

This publication is available free of charge from: https://doi.org/10.6028/NIST. NSRDS.73-2020

Appendix E

PREDEFINED REFRIGERANT BLENDS AVAILABLE IN REFLEAK

ASHRAE Components Composition Tcrit Tcrit

Designation (mass %) (C) (F)

R-401A R-22/152a/124 53/13/34 106.9 224.3 

R-401B R-22/152a/124 61/11/28 104.6 220.3

R-401C R-22/152a/124 33/15/52 111.7 233.1

R-402A R-125/290/22 60/2/38 74.8 166.6

R-402B R-125/290/22 38/2/60 82.1 179.7

R-403A R-290/22/218 5/75/20 84.0 183.2

R-403B R-290/22/218 5/56/39 75.4 167.8

R-404A R-125/143a/134a 44/52/4 72.1 161.8

R-405A R-22/152a/142b/C318 45/7/5.5/42.5 104.3 219.8

R-406A R-22/600a/142b 55/4/41 115.5 239.8

R-407A R-32/125/134a 20/40/40 82.3 180.1

R-407B R-32/125/134a 10/70/20 74.8 166.6

R-407C R-32/125/134a 23/25/52 86.1 187.1

R-407D R-32/125/134a 15/15/70 91.6 196.9 

R-407E R-32/125/134a 25/15/60 88.6 191.5

R-407F R-32/125/134a 30/30/40 82.6 180.7

R-407G R-32/125/134a 2.5/2.5/95 99.5 211.0

R-408A R-125/143a/22 7/46/47 82.9 181.3

R-409A R-22/124/142b 60/25/15 110.1 230.1

R-409B R-22/124/142b 65/25/10 107.6 225.7 

R-410A R-32/125 50/50 71.3 160.4

R-410B R-32/125 45/55 70.8 159.5

R-411A R-1270/22/152a 1.5/87.5/11.0 88.9 191.9

R-411B R-1270/22/152a 3/94/3 95.7 204.2

R-412A R-22/218/142b 70/5/25 107.1 224.8

R-413A R-218/143a/600a 9/88/3 95.3 203.6

R-414A R-22/124/600a/142b 51/28.5/16.5 111.4 232.5

R-414B R-22/124/600a/142b 50/39/1.5/9.5 110.7 231.3

R-415A R-22/152a 82/18 96.7 206.0

R-415B R-22/152a 25/75 109.9 229.9

R-416A R-124/R134a/600 39.5/59.0/1.5 106.3 223.3

R-417A R-125/134a/600 46.6/50.0/3.4 85.4 185.8

R-417B R-125/134a/600 79.0/18.3/2.7 74.1 165.3

R-417C R-125/134a/600 19.5/78.8/1.7 94.6 202.2

R-418A R-290/22/152a 1.5/96/2.5 95.6 204.2

R-419A R-125/134a/DME 77/19/4 83.5 182.3

R-419B R-125/134a/DME 48.5/48/3.5 91.1 196.0 

R-420A R-134a/142b 88/12 104.8 220.6

R-421A R-125/134a 58/42 82.8 181.0

R-421B R-125/134a 85/15 72.4 162.3

R-422A R-125/134a/600a 85.1/11.5/3.4 70.7 159.3

R-422B R-125/134a/600a 55/42/3 82.0 179.6

R-422C R-125/134a/600a 82/15/3 72.1 161.7

R-422D R-125/134a/600a 65.1/31.5/3.4 78.2 172.8

R-422E R-125/134a/600a 58/39.3/2.7 81.1 178.0

R-423A R-134a/227ea 52.5/47.5 99.1 210.5

R-424A R-125/134a/600a/600/601a 50.5/47/0.9/1/0.6 84.7 184.4

R-425A R-32/134a/227ea 18.5/69.5/12 93.9 210.4

R-426A R-125/134a/600/601a 5.1/93/1.3/0.6 99.0 210.2

R-427A R-32/125/143a/134a 15/25/10/50 85.5 185.9
19

This publication is available free of charge from: https://doi.org/10.6028/NIST. NSRDS.73-2020

ASHRAE Components Composition Tcrit Tcrit

Designation (mass %) (C) (F)

R-428A R-125/143a/290/600a 77.5/20/0.6/1.9 68.0 154.4

R-429A DME/152a/600a 60/10/30 122.0 251.5

R-430A R-152a/600a 6/24 107.0 224.6

R-431A R-290/152a 71/29 91.8 197.2

R-432A R-1270/DME 80/20 97.3 207.1

R-433A R-1270/290 30/70 94.4 201.9

R-433B R-1270/290 5/95 96.3 205.4

R-433C R-1270/290 25/75 94.8 202.6

R-434A R-125/143a/134a/600a 63.2/18/16/2.8 74.1 165.5

R-435A DME/152a 80/20 123.1 253.5

R-436A R-290/600a 56/44 115.9 240.6

R-436B R-290/600a 52/48 117.4 243.4

R-437A R-125/134a/600/601a 19.5/78.5/1.4/0.6 95.5 203.9

R-438A R-32/125/134a/600/601a 8.5/45/44.2/1.7/0.6 83.8 182.9

R-439A R-32/125/600a 50/47/3 70.3 158.6

R-440A R-290/134a/152a 0.6/1.6/97.8 112.7 234.8 

R-441A R-170/290/600a/600 3/55/6/36 118.5 245.2

R-442A R-32/125/134a/152a/227ea 31/31/30/3/5 82.1 179.9

R-443A R-1270/290/600a 55/40/5 96.0 204.8

R-444A R-32/152a/1234ze(E) 12/5/83 106.3 223.4

R-444B R-32/152a/1234ze(E) 41.5/10/48.5 95.7 204.2

R-445A R-744/134a/1234ze(E) 6/9/85 106.1 222.9

R-446A R-32/1234ze(E)/600 68/29/3 86.1 186.9

R-447A R-32/125/1234ze(E) 68/3.5/28.5 85.3 185.5

R-448A R-32/125/1234yf/134a/1234ze(E) 26/26/20/21/7 82.7 180.8

R-449A R-32/125/1234yf/134a 24.3/24.7/25.3/25.7 82.1 179.7

R-449B R-32/125/1234yf/134a 25/24/23/27 82.2 180.0

R-450A R-134a/1234ze(E) 42/58 104.5 220.0

R-451A R-1234yf/134a 89.8/10.2 94.4 201.9

R-451B R-1234yf/134a 88.8/11.2 94.3 201.7

R-452A R-32/125/1234yf 11/59/30 75.1 167.1

R-452B R-32/125/1234yf 67/7/26 77.1 170.8

R-452C R-32/125/1234yf 12.5/61/26.5 74.1 165.3

R-454A R-32/1234yf 35/65 81.7 179.1

R-454B R-32/1234yf 68.9/31.1 78.1 172.6

R-454C R-32/1234yf 21.5/78.5 85.7 186.2

R-455A R-744/32/1234yf 3/21.5/75.5 85.6 186.1

R-456A R-32/134a/1234ze(E) 6/45/49 102.7 216.9

R-457A R-32/152a/1234yf 18/12/70 91.3 196.3

R-458A R-32/125/134a/227ea/236fa 20.5/4/61.4/13.5/0.6 92.1 197.7

R-459A R-32/1234yf/1234ze(E) 68/26/6 79.6 175.3

R-460A R-32/125/134a/1234ze(E) 12/52/14/22 83.6 182.5

R-460B R-32/125/134a/1234ze(E) 28/25/20/27 88.1 190.5

R-500 R-12/152a 73.8/26.2 102.1 215.7

R-501 R-22/12 75/25 95.9 204.5

R-502 R-22/115 48.8/51.2 81.5 178.7

R-503 R-23/13 40.1/59.9 18.3 64.1

R-504 R-32/115 48.2/51.8 62.2 144.0

R-507A R-125/143a 50/50 70.6 159.1

R-508A R-23/116 39/61 10.2 50.3

R-508B R-23/116 46/54 11.2 52.2

R-509A R-22/218 44/56 68.5 155.2

R-510A DME/600a 88/12 125.7 258.2

R-511A R-290/DME 95/5 97.0 206.6
20

This publication is available free of charge from: https://doi.org/10.6028/NIST. NSRDS.73-2020

ASHRAE Components CompositionTcritTcrit

Designation (mass %) (C) (F)

R-512AR-134a/152a 5/95 112.8 235.1

R-513AR-1234yf/134a 56/44 94.9 202.8

R-513BR-1234yf/134a 58.5/41.5 94.8 202.6

R-515AR-1234ze(E)/227ea 88/12 108.2 226.7
21

This publication is available free of charge from: https://doi.org/10.6028/NIST. NSRDS.73-2020

Appendix F

CALCULATION OF INITIAL VOLUMETRIC QUALITY BASED ON FRACTION OF 

MAXIMUM LIQUID FILL

For fractionation analysis, ANSI/ASHRAE Standard 34 [6] specifies a container fill in terms of a “fraction 

of maximum fill” rather than a vapor volumetricquality. The maximum fill is the calculated mass that gives 

a 100 % liquid fill at the “fill temperature”, which the ASHRAE Standard specifies as 54.4 °C (130 °F). 

Note that this temperature may be different than the “initial leak temperature”. 

The REFLEAK main input window (Figure A-2) allows the user to use the ASHRAE specification of 

container fill and to calculate the resulting initial volumetric quality at the initial leak temperature. 

The following is the calculation procedure used by REFLEAK [7]. 

Input data

Original overall (bulk) blend composition

TF – liquid fill temperature [K]

FF – fraction of the maximum liquid fill at TF [fraction]

TL – initial leak temperature [K]

Other symbols used

 – density [kg/m3]

mliq – mass of refrigerant liquid [kg]

mvap – mass of refrigerant vapor [kg]

xq = mvap /( mvap + mliq ) - vapor quality [kg/kg]

Vliq – liquid volume per unit mass of the blend [m3/kg]

Vvap – vapor volume per unit mass of the blend [m3/kg]

Vq = Vvap /( Vvap + Vliq) - volumetric quality [m3/m3]

Subscripts

vap – vapor phase

liq – liquid phase

Calculation steps

1. Calculate the saturated liquid density at TF and the original blend composition, ρliq(TF)

2. Calculate the thermodynamic state point of the blend defined by: 

- original blend composition

 - initial leak temperature, TL

 - filling density of the refrigerant given by FF  ρliq(TF)

 

Results: 

- saturated vapor density at the coexisting vapor composition, ρvap(TL) 

 - saturated liquid density at the coexisting liquid composition, ρliq(TL)

- vapor quality, xq

3. Calculate the liquid and vapor volumes per unit mass of the blend

- liquid volume: Vliq(TL) = (1-xq)/ρliq(TL) 

- vapor volume: Vvap(TL) = xq/ρvap(TL) 

4. Calculate the volumetric quality, Vq(TL)

Vq(TL) = Vvap(TL)/[Vvap(TL) + Vliq(TL)] 
22

This publication is available free of charge from: https://doi.org/10.6028/NIST. NSRDS.73-2020

Appendix G

CONTACTS

If you have comments or questions about the database, the Standard Reference Data Program would 

like to hear from you. Also, if you should have any problems with the installation, please let us know by 

contacting:

SRD Customer Support

National Institute of Standards and Technology

100 Bureau Drive, Stop 6410

Gaithersburg, MD 20899-6410

Tel: 1(844) 374-0183 (Toll Free)

e-mail: data@nist.gov

If you have questions or problems pertaining to the use of the database, contact:

Piotr A. Domanski

National Institute of Standards and Technology

Engineering Laboratory

100 Bureau Drive, Stop 8631

Gaithersburg, MD 20899-8631

Tel: 1 (301) 975-5877

e-mail: piotr.domanski@nist.gov