EPA/600/A-97/025
970525
Evaluation of lkon@-12 Refrigerant for Motor
Vehicle Air Conditioning
James J. Jetter and N. Dean Smith
U.S. Environmental Protection Agency
Krich Ratanaphruks, Angelita S. Ng, Michael W. Tufts, and Francis R. Delafield
Aeurex Environmental Corporation
Abstract
A proprietary refrigerant, called lkon®-12, was
evaluated as an alternative to HFC (hydrofluorocarbon)-
134a for automotive air conditioning. The evaluation was
motivated by concern over the relatively high global
warming potential of HFC-134a. In preliminary tests,
ikon®-12 was found to be compatible with a polyolester
lubricant and engineering materials. Refrigeration
capacity and efficiency for lkon®-12 compared favorably to
those for HFC-134a. In a preliminary durability test, Ikon®-
12 refrigerant showed no significant chemical breakdown
after extended operation with an elevated compressor
discharge temperature. Further testing would be required
to determine if stability and materials compatibility are
acceptable for long-term use.
Introduction
HFC-134a is currently used as the refrigerant in
new and retrofitted motor vehicle air conditioners,
replacing the stratospheric ozone depleting refrigerant,
CFC (chlorofluorocarbon)-l 2. Although HFC-134a has no
ozone depletion potential, it has a global warming
potential approximately 3300 times that of C02 (carbon
dioxide) over a 20 year time horizon, 1300 times that of
C02 over a 100 year time horizon, or 420 times that of
COa over a 500 year time horizon.1 By the year 2005,
approximately 260 million vehicles with HFC-134a air
conditioners will be in service in developed countries and
will require an estimated 74,800 metric tons of refrigerant
annually including 33,400 metric tons for new vehicles and
41,400 metric tons for service usage.2 Refrigerant
emissions due to service usage represent an annual, C02-
equivalent of 53.8 million metric tons, based on a 100 year
time horizon. In 1994, the estimated total U.S.
greenhouse gas emissions were 6109 million metric tons
C02-equivalent.3 Increased concern over global climate
change could eventually lead to restrictions on HFC-134a
consumption. For this reason, the U.S. EPA
{Environmental Protection Agency) has evaluated
alternatives for HFC-134a in motor vehicle air
conditioning.4
A proprietary, near-azeotropic blend of an FIC
(fluoroiodoearbon) and an HFC, called lkon®-12, has been
proposed as a refrigerant for automotive air conditioning
and other applications.5 The global warming potential for
lkon®-12 has been reported to be 4 percent of that for
HFC-134a.5 Ikon®-12 has been reported to be
nonflammable according to testing based on ASTM
(American Society for Testing and Materials) methods
E681-85 and E918-83.6"7 Extensive toxicity testing has
been reported for both components of the refrigerant
blend. Reported results have been generally favorable,
although toxicity may be somewhat higher than for HFC-
134a. Under EPA's SNAP (Significant New Alternatives
Policy) Program, lkon®-12 has been approved for use in
motor vehicles subject to use conditions including the use
of unique fittings, the use of descriptive labels, a
prohibition against topping off one refrigerant with another,
and appropriate recovery or recycling equipment.8
Lubricant Miscibility
Miscibility was tested for the lkon®-12 refrigerant
with a PAG (polyalkylene glycol) lubricant and a POE
(polyolester) lubricant. The PAG lubricant was supplied
by an OEM (original equipment manufacturer). Its
viscosity was reported to be 135 cSt at 40°C and 25 cSt
at 100°C. It was reported to contain proprietary additives.
The POE lubricant was supplied by a chemical
manufacturer. Its viscosity was reported to be 134 cSt at
40°C and 15 cSt at 100°C. It also contained proprietary
additives. Sealed glass tubes were prepared with the
lkon®-12 refrigerant and lubricant at lubricant
concentrations of 2, 5,10, 20, and 30 weight percent.
1

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Complete miscibility with the PAG lubricant was
found at low temperatures with all sample concentrations
remaining miscible down to -45°C. However, separation
of the refrigerant and PAG iubricant occurred at
approximately 95°C for the 2 and 5 weight percent
samples. The 10, 20, and 30 weight percent samples
remained miscible up to 125°C, at which point the test
was terminated.
Miscibility with the POE lubricant was tested over
the temperature range of -45 to +115"C. No phase
separation was observed for all concentrations, indicating
complete miscibility of the lkon®-12 refrigerant and the
POE lubricant at the conditions tested.
Stability and Materials Compatibility
As a preliminary evaluation of the thermal and
hydrolytic stability of Ikon®-12 and its compatibility with
common materials of construction used in automotive air
conditioners, sets of sealed glass tube samples were
prepared. Materials were selected in preparation for
testing the refrigerant in an automotive air-conditioning
system designed for HFC-134a. Materials compatibility
and stability were tested in accordance with the methods
described in ANSI/ASHRAE Standard 97-1989.9 Stability
tests were conducted by sustained heating of the lkon®-12
refrigerant by itself and with copper, aluminum, and steel
in sealed glass tubes at 175°C for 14 days. Compatibility
tests were conducted by sustained heating of elastomers,
polymers, desiccant, cast iron, and brass with the
refrigerant at 125°C for 14 days. One set of tubes was
prepared without any lubricant, one set was prepared with
PAG lubricant, and one set was prepared with POE
lubricant. Duplicate samples were prepared and tested for
each combination.
Sealed tubes containing lkon®-12 refrigerant by
itself were visually inspected after sustained heating at
175°C for 14 days. The fluid changed from colorless to
purple color, indicating the presence of iodine. Voiatiles
released upon breaking the tubes under vacuum were
analyzed by gas chromatography, mass spectrometry,
and infrared spectrometry. The resultant chromatograms
and spectra were compared to those obtained for pure
refrigerant. A small amount of breakdown of the FIC was
found as evidenced by the formation of a minute quantity
of CF3H (trifluoromethane). The addition of copper,
aluminum, and steel did not affect the results significantly.
The addition of a small amount of water also did not affect
the results.
Sealed tubes containing Ikon®-12 refrigerant in
combination individually with buna-n, neoprene, 6/6 nylon,
Teflon, cast iron, and brass were maintained at a
temperature of 125°C for 14 days. Chemical analysis of
the voiatiles released from those tubes indicated the
formation of a minute amount of CF3H.
Visual inspection of sealed tubes containing Ikon®-
12 and PAG lubricant showed substantial decomposition
as evidenced by the presence of carbonized solids after
the 14-day aging period. Vapor-phase contents of one
tube containing only the lkon®-12 and PAG lubricant were
analyzed by gas chromatography and mass spectrometry.
A host of degradation products were evident from the
analyses indicating that the incompatibility of lkon®-12 and
PAG lubricant was independent of the presence of other
materials. Vapor-phase components identified from the
analyses suggest that the PAG lubricant and both
components of the Ikon®-12 blend decomposed. Analysis
of the contents of other tubes containing materials with the
PAG lubricant was not continued because of the obvious
instability. The PAG lubricant was considered
unacceptable for use with the lkon®-12 refrigerant.
Sealed tubes containing lkon®-12 and the POE
lubricant appeared from visual inspection to have better
chemical stability than the tubes containing the PAG
lubricant. Stability of the refrigerant and lubricant
combination was tested by sustained heating at 175°C for
14 days. Voiatiles released upon breaking the tubes were
analyzed. The addition of the POE lubricant resulted in a
greater decomposition of the FIC than without the
lubricant, but only a relatively small amount of
decomposition was found. Further work would be
required to quantify the decomposition. For comparison,
HFC-134a with PAG lubricant typically has no discernible
breakdown at 175°C. However, mineral oil lubricant used
with CFC-12 refrigerant typically has substantial
breakdown at 175°C.
When copper, aluminum, and steel were added to
the mixture of refrigerant and lubricant, greater
decomposition of the FIC was found as evidenced by the
formation of larger concentrations of CF3H and the
deposition of salts on the metal surfaces. The
combination of !kon®-12, POE lubricant, and metals also
yielded trace amounts of CO (carbon monoxide) and
monofluoroethene. The presence of the
monofluoroethene indicated a probable degradation of the
HFC component of the refrigerant blend.
Sealed tubes containing Ikon®-12 and the POE
lubricant in combination individually with buna-n,
neoprene, 6/6 nylon, Teflon, XH-7 desiccant, cast iron,
and brass were maintained at a temperature of 125°C for
14 days. Chemical analysis of the voiatiles released from
those tubes indicated a small amount of decomposition of
the refrigerant. In the presence of the desiccant, there
was a very slight formation of monofluoroethene, again
indicating a probable degradation of the HFC component
of the refrigerant blend.
Data for materials tested with lkon*-12 in sealed
tubes with and without POE lubricant are summarized in
Table 1. Average values for each pair of tubes are
reported. Hardness values were not obtained for nylon

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Table 1. Materials Compatibility Test Results
Material
Weight Change
(Percent)
Volume Change
(Percent)
Linear Swell
(Percent)
Dia. Change
(Percent)
Hard. Change
(Percenjt)
Buna-N
+ 37.2
+ 8.4
+ 9.6
+ 4.1
+ 7.3
Buna-N (with POE lube)
+ 20.1
+ 10.0
+ 5.7
+ 4.9
+ 12.9
Neoprene
+12.5
+7.5
+2.8
+2.3
+13.7
Neoprene (with POE lube)
+7.3
+10.2
+2.7
+4.1
+2.1
Teflon
+ 4.8
-8.9
+ 5.2
-4.6
not tested
Teflon (with POE lube)
+ 2.7
-6.4
+ 4.7
-3.3
not tested
Nylon 6/6
+ 12.9
+ 5.8
+1.1
not tested
not tested
Nylon 6/6 (with POE lube)
-9.4
-10.1
-4.4
not tested
not tested
arid Teflon since these harder materials were not
amenable to the test method. With the POE lubricant,
both Teflon and nylon shrank in volume while buna-n
swelled in volume. For Teflon and nylon, volume change
was excessive compared to generally accepted criteria for
volume change from -5 to +25 percent.
It was concluded that the stability and
compatibility of the lkon®-12 refrigerant and POE lubricant
combination were adequate to proceed with performance
testing at temperatures not exceeding 125°C. Further
laboratory and field testing would be required to determine
if stability and materials compatibility are acceptable for
long-term use.
Refrigeration Capacity and Energy Efficiency
Refrigeration capacity and COP (coefficient of
performance) were experimentally determined for lkon®-12
and for HFC-134a with an instrumented, automotive air-
conditioning system. Instrumentation was similar to that
described in a previous paper.10 The automotive air-
conditioning system was an OEM unit designed for HFC-
134a. Refrigeration capacity was measured with an
uncertainty of approximately ±100W and a repeatability of
approximately ±30W. COP was determined from the
measured power input to the compressor with an
uncertainty of approximately ±75W and a repeatability of
±50W.
The OEM air-conditioning system had a suction
line accumulator and orifice tube expansion device.
Refrigerant was added to the system until liquid was
present in the accumulator as indicated by minimal
superheat at the compressor inlet. The refrigerant charge
size was 920 g for HFC-134a and 1520 g for lkon®-12.
The same orifice tube was used for both refrigerants.
Approximately the same amount of subcooling was
measured at the orifice tube inlet for both refrigerants at
each test condition. Test results are shown in Figure 1.
Refrigeration capacity and COP for lkon®-12 and HFC-
134a were measured at three compressor rotational
speeds, three evaporating temperatures, and three
condensing temperatures. Over the range of test
conditions, refrigeration capacity for Ikon®-12 averaged 5
percent higher than for HFC-134a. COP for lkon®-12
averaged 11 percent higher than for HFC-134a.
Compressor discharge temperatures with lkon®-12
averaged 2°C higher than with HFC-134a. Over the
range of test conditions, the compressor discharge
temperature with lkon®-12 varied from 0.8°C lower to 6°C
higher than with HFC-134a.
Durability
Following the performance tests, the test system
was run for an extended period of time with an elevated
compressor discharge temperature to determine if
refrigerant decomposition would occur. Test conditions
were adjusted to obtain a compressor discharge
temperature of 110°C. Compressor suction pressure was
338 kPa and discharge pressure was 2614 kPa.
Compressor rotational speed was 2050 rpm, and
compressor ambient temperature was 70°C. After 192
hours of continuous operation at those conditions,
mechanical failure of a compressor suction reed valve
occurred. The lkon®-12 refrigerant was recovered from
the system, and the compressor was disassembled and
inspected. The broken reed valve damaged the cylinder
surface, but there was no evidence of excessive wear or
any other problem. Failure of the reed valve was
apparently caused by metal fatigue due to the severe
operating conditions. The lubricant remained clear, and
no deposits were found on the internal surfaces of the
compressor.

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f
Evaporating Temperature (° C)
-1,1 4,4 10.0
HFC-134a
ikon-12

5 6,000
« 4,000
s
S 2,000
50 55 60 65
Condensing Temperature f C)
Refrigeration Capacity, 1000 rpm
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C
c
E
i2
Ss. "u—i


V Xv' -i
S.
¦
Vv\\
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, ! r.„ I 	 		-				I	i	I
40 45 50 55 60 65 70
Condensing Temperature (°C)
75
Coefficient of Performance, 1000 rpm
3
£2
1
0
50 55 60 65
Condensing Temperature (°C)
40
& 6,000
4,000
2,000
0
70
40
45
65
Condensing Temperature (°C)
55
75
Condensing Temperature ('
Refrigeration Capacity, 2000 rpm	Coefficient of Performance, 2000 rpm
£2
40
75
Condensing Temperature (°C)
§6,000
.» 4,000
2,000
70
75
45
Condensing Temperature (° C)
Refrigeration Capacity, 3000 rpm	Coefficient of Performance, 3000 rpm
Figure 1. Refrigeration Capacity and Coefficient of Performance of Ikon-12 Compared to HFC-134a
4

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Following the compressor failure, samples of
refrigerant and lubricant were analyzed. Vapor- and
liquid-phase materials were analyzed with gas
chromatography, mass spectrometry, and infrared
spectrometry. The resultant chromatograms and spectra
were compared to those obtained for pure refrigerant and
lubricant. There was no evidence of refrigerant
breakdown in the vapor or liquid. Purity of the lkon®-12
was greater than 99.5 percent.
The failed compressor was replaced with a
similar, new compressor. Before installation, PAG
lubricant was flushed from the new compressor with POE
lubricant, and approximately 40 ml of the new POE
lubricant was added to the new compressor to replace the
amount removed with the failed compressor. The total
amount of lubricant in the air-conditioning system was
approximately 240 m!. The same lkon®-12 refrigerant
used for the previous testing was recharged into the
system. Test conditions were adjusted to maintain the
110°C compressor discharge temperature, but the
compressor rotational speed was reduced to prevent
premature failure of the valves. Compressor rotational
speed was 1000 rpm, and compressor ambient
temperature was 90°C. Compressor suction pressure
was 479 kPa and discharge pressure was 2867 kPa.
Refrigerant and lubricant samples were analyzed
after 467 hours and again after 632 hours of operation,
including the 192 hours of operation on the first
compressor. Gas chromatography/mass spectrometry
analyses of the refrigerant vapor and gas
chromatography/Fourier transform infrared analyses of the
lubricant showed no significant changes over the 632 hour
period.
After 732 hours of operation, a leak in a refrigerant
line resulted in the loss of the refrigerant charge. A
lubricant sample was analyzed with gas
chromatography/Fourier transform infrared, and no
significant change was found. During inspection of the
test system, it was found that the compressor shaft could
not be rotated by hand. When torque was applied to the
compressor shaft with a wrench, the moving parts
loosened, and the shaft could then be turned by hand.
The compressor was disassembled and inspected. A
dark, viscous fluid was found in small quantities on some
bearing surfaces and in some cavities inside the
compressor. No excessive wear was found on any
surfaces, and no indication of mechanical failure was
observed. Lubricant found inside the compressor
remained clear. Since no similar dark substance was
found inside the first compressor after 192 hours of
operation, and since lkon®-12 refrigerant was known to be
incompatible with PAG lubricant, it was suspected that the
foreign substance resulted from a small amount of PAG
lubricant remaining in the second compressor after
flushing. An infrared spectral analysis of the dark, viscous
fluid exhibited general features resembling both PAG and
POE lubricants. However, the fluid could not be
unambiguously traced to residual PAG lubricant left in the
compressor. Further durability testing and chemical
analyses were beyond the scope of the project. Further
testing would be required to determine if stability and
durability are acceptable for long-term use.
Summary
1.	A proprietary, near-azeotropic, low-GWP, refrigerant
blend of an FIC and an HFC, called Ikon*-12, was
evaluated as an alternative to HFC-134a for automotive
air conditioning. The evaluation was motivated by
concern over the relatively high global warming potential
of HFC-134a,
2.	lkon®-12 was not compatible with a PAG lubricant, but
was sufficiently compatible and stable with a POE
lubricant and engineering materials to proceed with testing
in an automotive air-conditioning system. Over the
temperature range of -35 to +100°C, the lkon®-12
refrigerant was completely miscible with the POE
lubricant.
3.	Refrigeration capacity and COP were determined
experimentally with an instrumented, OEM, automotive
air-conditioning system. Refrigeration capacity for Ikon®-
12 averaged 5 percent higher than for HFC-134a over the
range of test conditions. COP for lkon®-12 averaged 11
percent higher than for HFC-134a.
4.	Durability of the refrigerant and lubricant was tested by
operating the test system with an elevated compressor
discharge temperature. During the course of the testing,
a compressor suction reed valve was broken. Failure of
the reed was apparently caused by metal fatigue due to
the severe operating conditions. After 632 hours of
operation with a discharge temperature of 110°C, no
significant breakdown of the refrigerant or lubricant was
detected from chemical analyses by gas chromatography,
mass spectroscopy, and infrared spectroscopy.
5.	Following the durability test, the compressor was
disassembled and inspected. A small quantity of dark,
viscous fluid was found inside the compressor and may
have been caused by residual PAG lubricant. However,
the fluid could not be positively identified by chemical
analyses.
6.	Further laboratory and field testing would be required to
determine if stability and materials compatibility are
acceptable for long-term use.
Acknowledgments
The authors wish to acknowledge the assistance
of Jon Nimitz of The Ikon Corporation, who provided
information on the Ikon®-12 refrigerant; and of Georgi S.

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Kazachki of Acurex Environmental Corporation, who
provided technical consultation for performance testing.
Alternatives Conference. Washington, D.C. 1994. Pages
785-794,
References
1.	Radiative Forcing of Climate Change, the 1994 Report
of the Scientific Assessment Working Group of IPCC.
Intergovernmenta! Panel on Climate Change. 1994.
Page 28.
2.	1994 Report of the Refrigeration, Air Conditioning and
Heat Pumps Technical Options Committee for the 1995
Assessment of the Montreal Protocol on Substances that
Deplete the Ozone Layer. United Nations Environment
Programme. 1994. Pages 163-183.
3.	Inventory of U.S. Greenhouse Gas Emissions and
Sinks: 1990-1994. U.S. EPA Office of Policy, Planning
and Evaluation. Washington, D.C. EPA-230-R-96-006
(NTIS PB96-175997). 1995. Page 4.
4.	Jetter, J.J., Smith, N.D., Ratanaphruks, K., Ng, A.S.,
Tufts, M.W., Delafield, F.R. "Evaluation of Alternatives for
HFC-134a Refrigerant in Motor Vehicle Air Conditioning."
Proceedings of the 1996 International Conference on
Ozone Protection Technologies. Washington, D.C. 1996.
Pages 845-854.
5.	Significant New Alternatives Policy (SNAP) Program
Submission to the U.S. Environmental Protection Agency,
Ikon9-12 Refrigerant, Docket Copy, For Public Release.
Submitted March 6, 1995 by Jon Nimitz, The Ikon
Corporation.
6.	Standard Test Method for Concentration Limits of
Flammability of Chemicals, ASTM Designation: E681-85
(Reapproved 1991). American Society for Testing and
Materials. Philadelphia. 1991.
7.	Determining Limits of Flammability of Chemicals at
Elevated Temperatures and Pressures, ASTM
Designation: E918-83 (Reapproved 1988). American
Society for Testing and Materials. Philadelphia. 1988.
8.	"Protection of Stratospheric Ozone: Listing of
Substitutes for Ozone-Depleting Substances." Federal
Register. Volume 61, Number 100. May 22, 1996.
Pages 25585-25594.
9.	ANSI/ASHRAE Standard 97-1989, Sealed Glass Tube
Method to Test the Chemical Stability of Material For Use
Within Refrigerant Systems. American Society of Heating,
Refrigerating and Air-Conditioning Engineers. Atlanta,
Georgia. 1989.
10.	Jetter, J.J,, Delafield, F.R. "Retrofitting an Automotive
Air Conditioner with HFC-134a, Additive, and Mineral Oil."
Proceedings of the 1994 International CFC and Halon

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MR 1\/TPT -PTP-*D-1^0 TECHNICAL REPORT DATA
iNnivxrtJ^ nil r l da (Please read Instructions on the reverse before completing)
—
1. REPORT NO. 2.
EPA/600/A-97/025
3. REC
4. TITLE AND SUBTITLE
Evaluation of Ikon-12 Refrigerant for Motor Vehicle
Air Conditioning
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7.author(s) j_ Jetter and N. D. Smith (EPA); and K.
Ratanaphruks, A. S. Ng, M. W. Tufts, and F. R.
Delafield (Acurex)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
Acurex Environmental Corporation
4915 Prospectus Drive
Durham, North Carolina 27713
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D4-0005
12. SPONSORING AGENCY NAME ANO ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NO 27711
13. TYPE OF REPORT AND PERIOD COVERED
Published paper; 10/95-6/96
14. SPONSORING AGENCY CODE
EPA/600/13
is. supplementary notes ^ppcjj project officer is James J. Jetter, Mail Drop 63, 919/
541-4830. For presentation at 1997 SAE International Congress and Exposition,
2/24-27/97, Detroit. MI.
is. abstractpaper gives results of an evaluation of a proprietary refrigerant, Ikon-
12, as an alternative to hydrofluorocarbon (HFC)-134a for automotive air condition-
ing. The evaluation was motivated by concern over the relatively high global warming
potential of HFC-134a. In preliminary tests, Ikon-12 was found to be compatible with
a polyolester lubricant and engineering materials. Refrigeration capacity and effi-
ciency for Ikon-12 compared favorably to those for HFC-134a. In a preliminary dura-
bility test, Ikon-12 refrigerant showed no significant chemical breakdown after exten-
ded operation with an elevated compressor discharge temperature. Further testing
would be required to determine if stability and materials compatibility are acceptable
for long-term use.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. cosati Field/Group
Pollution
Refrigerants
Motor Vehicles
Air Conditioning
H alohydrocarbons
Greenhouse Effect
Climatic Chances
Pollution Prevention
Mobile Sources
Ikon-12
Hydrofluorocarbons
Global Warming
13 B
13 A
13 F
07C
04A
04R
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)

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