EPA/600/A-97/012
CALORIMETER PERFORMANCE TESTS OF HFC-245ca
AND HFC-245fa AS CFC-11 REPLACEMENTS
Georgi S. Kazachki1, Cynthia L. Gage2, Evren Bayoglu1, and Robert V. Hendriks2
'Acurex Environmental Corporation, P.O. Box 13109, Research Triangle Park, NC 27709
2U,S. Environmental Protection Agency, National Risk Management Research Laboratory,
Research Triangle Park, NC 27711
Abstract
As an ozone-depleting chemical and a Class I substance under the Montreal Protocol,
chlorofiuorocarbon (CFC)-l 1 can no longer be manufactured in developed countries for use in
those countries. This refrigerant was the main chemical used in low-pressure chillers. The
phaseout of CFC-11 has led to the use of hydrochlorofluorocarbon (HCFC)-123 as the refrigerant
of choice in new low-pressure chillers. However, HCFC-123 is a Class II substance under the
Protocol and will eventually be phased out, too. Therefore there is a need to identify non-
chlorine-containing alternatives for use in low-pressure chillers.
Early thermodynamic investigations indicated the potential of several hydrofl uorocarbon
(HFC) chemicals, including HFC-245ca and HFC-245fa, as non-chlorine-containing options.
These investigations showed that HFC-245ca had lower volumetric capacity and cycle efficiency
than CFC-11, while HFC-245fa had significantly higher volumetric capacity but slightly lower
cycle efficiency.
The present work presents the results of compressor calorimeter tests with HFC-245ca
and HFC-245fa as CFC-11 alternatives. Tests were performed in a semihermetic compressor at
evaporating temperatures from 1 to 13C and condensing temperatures from 40 to 60C. In these
ranges, the capacities and efficiencies of HFC-245ca were confirmed to be lower than CFC-11,
while both capacities and efficiencies of HFC-245fa were significantly higher. The higher-than-
expected efficiencies and capacities for HFC-245fa were a result of the higher compressor
efficiencies. If the higher condensing pressures for HFC-245fa could be found to be acceptable
to low-pressure chiller manufacturers, this refrigerant would be a viable alternative.
Background
Under the Montreal Protocol and Clean Air Act Amendments of 1990, CFC-11 can no
longer be manufactured in developed countries for their use in low-pressure chillers. The short-
term alternative for this compound is HCFC-123, which itself is under the phaseout schedule
since it is a Class II substance. In earlier studies, the search for non-chlorine containing
alternatives for CFC-11 and HCFC-123 resulted in the identification of several potential
alternatives, including HFC-245ea and HFC-245fa (1,2).
Preliminary analysis of material compatibility, toxicity, flammability, and atmospheric
lifetime for HFC-245ca indicated favorable results in the absence of moisture (3). High moisture
content resulted in some compatibility problems with the limited set of elastomers investigated.

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In addition, HFC-245ca was observed to be flammable in air with high relative humidity, with
the range of flammability sensitive to the moisture content.
Preliminary analyses of material compatibility, flammability, and atmospheric lifetime
have also been performed with HFC-245fa(4). Of the 13 elastomeric materials tested, three gave
satisfactory performance. Atmospheric lifetime was also found to be acceptable. As with HFC-
245ca, HFC-245fa was found to be mildly flammable in the presence of moisture; however,
based on the proposed modifications to ASTM E681-85 and ASHRAE Standard 34-1992
flammability tests, HFC-245fa is expected to be rated non-flammable(5).
The theoretical analysis of both HFC-245 isomers included thermodynamic evaluations in
a vapor-compression cycle and calculations of centrifugal compressor characteristics^). As with
the short-term alternative, HCFC-123, isentropic compression of the HFC-245 isomers from
saturated vapor was found to result in the potential for wet compression with HFC-245ca having
the greatest potential of the three refrigerants. Comparison of performance in a cycle with
throttling and dry compression indicated that the volumetric capacity of HFC-245ca was about
13% lower than for CFC-11, while the capacity of HFC-245fa was about 30% higher. Cycle
efficiencies for HFC-245ca and HFC-245fa were, respectively, 5 and 4% lower than for CFC-11.
It was also noted that, at 40C, the condensing pressure for HFC-245fa was about 70 kPa higher
than for CFC-11.
In an earlier study a calorimeter test was performed on HFC-245ca in an oil-free
compressor at one test condition, 4.4C evaporating and 40.6C condensing temperatures(6).
Equipment and Test Method
Experimental evaluation of the CFC-11 alternatives was done on a compressor
calorimeter test rig with a semihermetic compressor. The original calorimeter was modified for
low-pressure refrigerants to eliminate excessive pressure drops. These modifications were
detailed in an earlier publication(7). The semihermetic compressor had a 0.56 kW motor and
delivered 1.329 L/s at 1750 RPM. The compressor was designed for use with HFC refrigerants
and was lubricated by polyolester oil.
Tests were performed using ASHRAE Standard 23-1993(8) as a basis. The cooling
capacity was determined by two methods: a primary method based on the quantity of electrically
supplied heat to the calorimeter boiler and a secondary method based on the heat balance of the
water-cooled condenser. Agreement between the two methods was acceptable. Each test
condition was evaluated three times, and the resulting values were averaged. The standard
deviation of the average value for any given parameter was never greater than 2%.
i
Tests were performed at evaporating temperatures from 1 to 13C and condensing
temperatures from 40 to 60C. A few degrees of subcooling was achieved in the condenser to
ensure liquid feeding to the expansion valve. Similarly some superheating was achieved in the
evaporator to ensure that no liquid reached the compressor to avoid wet compression. All results
were corrected back to conditions of saturated liquid leaving the condenser and saturated vapor
leaving the evaporator.
9

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Experimental Results
Table 1 shows typical compressor calorimeter results for HFC-245fa at 12.8C
evaporating and 40.6C condensing temperatures. Similar tables were generated at all test
conditions for both HFC-245fa and HFC-245ca. All graphical results for both refrigerants are
presented relative to the results for CFC-11 in the same compressor.
Figures 1 and 2 show the results for relative cooling capacity of HFC-245ca and HFC-
245fa, respectively. As expected from the theoretical analyses, the capacity of the ca-isomer is
lower than that of CFC-11, while the fa-isomer has significantly higher cooling capacity with
measured values ranging from 30 to 50% higher. The higher-than-expected capacities for HFC-
245fa are a result of the higher compressor volumetric efficiencies, presented later. The
compressor electrical input for the two refrigerants is shown in Figures 3 and 4. The required
input for HFC-245ca was about the same as for CFC-11, while HFC-245fa required higher input.
Figures 5 and 6 present the compressor's energy efficiency ratio (EER) for the two
refrigerants relative to CFC-11. The lower capacity for the ca-isomer results in EER values from
3 to 18% lower than for CFC-11. For the fa-isomer, as with the cooling capacity, the EER is
significantly higher than CFC-11. Measured values ranged from 10 to 28% higher. Lower EER
for HFC-245ca was expected from the theoretical analysis; however, the EER for HFC-245fa
was higher than expected.
Compressor isentropic and volumetric efficiencies are shown in Figures 7 through 10.
For HFC-245ca, the compressor isentropic energy efficiency is from 2 to 12% lower than for
CFC-11, while volumetric efficiencies are close to those for CFC-11. For HFC-245fa, both
compressor efficiencies are from 4 to 30% higher than for CFC-11. These higher efficiencies
contribute to the higher-than-expected cooling capacity and EER.
Figures 11 and 12 present the compression ratios. Both isomers have higher compression
ratios than CFC-11, with the ca-isomer averaging about 16% higher and the fa-isomer averaging
about 8% higher.
Conclusions
1.	Compressor calorimeter tests confirmed that both HFC-245ca and HFC-245fa are viable
alternatives to replace CFC-11.
2.	As expected, both the compressor cooling capacity and the EER with HFC-245ca were less
than with CFp-11. With HFC-245fa, both parameters were significantly higher than with
CFC-11 and higher than expected.
3.	Compressor isentropic energy and volumetric efficiencies were lower than CFC-11 for HFC-
245ca and higher for HFC-245fa.
4.	With its superior performance, HFC-245fa could be a strong replacement candidate, if the
higher condensing pressures could be accepted by chiller manufacturers.
3

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References
1.	Kazachki, G.S., "Thermodynamic Evaluation of Fluorinated Ethers, Ethanes, and Propanes as
Alternative Refrigerants," presentation at the 1991 International CFC and Halon Alternatives
Conference, Baltimore, MD, December 1991.
2.	Kazachki, G.S. and C.L. Gage, "Thermodynamic Evaluation and Compressor Characteristics
of HFC-236ea and HFC-245ca as CFC-114 and CFC-11 Replacements in Chillers," Proceedings
of the 1993 International CFC and Halon Alternatives Conference, Washington, DC, October
1993.
3.	Smith, N.D., K. Ratanaphruks, M.W. Tufts, and A.S. Ng, "R-245ca: A Potential Far-term
Alternative for R-ll," ASHRAE Journal 35:2, pp. 19-23, February 1993.
4.	Smith, N.D., A.S. Ng, M.W. Tufts, A.M. Drago, and K. Ratanaphruks, "Evaluation of HFC-
245fa as a Potential Alternative for CFC-11 in Low Pressure Chillers," Proceedings of the 1994
International CFC and Halon Alternatives Conference, Washington, DC, October 1994.
5.	Smith, N.D., Private communication, U.S. EPA, NRMRL, Research Triangle Park, NC, July
1996.
6.	Kazachki, G.S. and R.V. Hendriks, "Calorimeter Tests of HFC-236ea as a CFC-114
Alternative and HFC-245ca as a CFC-11 Alternative," Proceedings of the 1993 International
CFC and Halon Alternatives Conference, Washington, DC, October 1993.
7.	Kazachki, G.S. and R.V. Hendriks, "Performance Testing of a Semi-hermetic Compressor
with HFC-236ea and CFC-114 at Chiller Conditions," Proceedings of the 1994 International
Refrigeration Conference at Purdue University, West Lafayette, IN, July 1994.
8.	ASHRAE Standard 23-1993, "Methods of Testing for Rating Positive Displacement
Refrigerant Compressors and Condensing Units," American Society of Heating, Refrigerating
and Air-Conditioning Engineers, Atlanta, GA, 1993.
A

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ABLE 1:
TEST CONDITIONS AND MAIN RESULTS FROM THE CALORIMETER TESTS OF A SEMI-HERMETIC COMPRESSOR WITH
HFC-245fa:
ymbols: p, - suction pressure, kPa; p2 - discharge pressure, kPa; TE - nominal evaporating temperature, C; Tc - nominal condensing
temperature, ClTei - temperature at the evaporator inlet, C; TEsat - evaporating saturation temperature at suction pressure, C; Tev -
temperature at the expansion valve inlet, C; TCtlt - condensing saturation temperature at discharge pressure, C; TCI - temperature at the
condenser inlet, C; T, - temperature at the compressor inlet, C; T2 - temperature at the compressor outlet, C; T0IL - oil temperature at
the sump bottom, C; QEP - cooling capacity from the primary method at the real conditions, W; 6QESC - relative deviation of the secondary
condenser method from the primary method, %; P - electrical input power into the compressor at the real conditions, W; V - Voltage, V;
lc - Compressor motor current, A; EER - Energy efficiency ratio, Btu/W.h; PR -Pressure ratio; Ac - Compressor volumetric efficiency, %;
nc - Compressor energy efficiency, %; o - standard deviation.
lemarks: 1. Test conditions: TE = 12.8C, Tc = 40.6C
2.	Date of tests: 06/14/96
3.	Oil circulation not measured,
U1
Test
Pi
P2
tb
T*Esat
Tc,
T"csat
Tb/
T,
t2
Toil
qep
5Q6sc
Pe>
V
'c
EER
PR
Ac
He
C96-0043
90.52
250.5
11.4
12.6
57.4
40.5
19.2
18.1
59.7
46.9
1004.7
3.6
412.0
115.0
6.31
8.35
2.77
89.75
27.46
C96-0044
90.73
251.2
11.4
12.7
57.8
40.6
19.1
18.8
60.1
47.2
1007.6
3.3
412.0
115.0
6.32
8.36
2.77
90.10
27.64
C96-0045
90.39
251.2
11.3
12.6
58.0
40.6
19.2
18.8
60.3
47.2
1003.4
3.1
410.0
115.0
6.28
8.35
2.78
90.09
27.72




















Avg
90.55
251.0
11.4
12.6
57.7
40.6
19.2
18.6
60.0
47.1
1005.2
3.3
411.3
115.0
6.30
8.35
2.77
89.98
27,61
o
0.14
0.3
0.0
0.0
0.3
0.0
0.0
0.3
0.2
0.1
1.8
0.2
0.9
0.0
0.02
0.00
0.00
0.16
0.11

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0.94 -
fc 0,98
O
< 0.96
^ '
U
o 0.92 -
 0,9
o	0.88 -
gj 0.86 -
P 0.84
rf 0.82
Tc=40.6C -*- Tc=46.1C Tc=54,4C  Tc=60C

0 2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 1. Compressor Cooling Capacity with
HFC-245ca Relative to CFC-11.
14
1.03
Tc=40.6C ~ Tc=46.1C > Tc=54.4C . Tc=60C
w 1.01
H
d 0.99 4-
0.98 J
 2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 3. Compressor Electrical Input with
HFC-245ca Relative to CFC-11.
1.55
Tc=40.6C Tc=46.1C  Tc=54.4C . Tc=60C
P 1.35
0
2
4
6
8
10
12
14
EVAPORATING TEMPERATURE (C)
Figure 2. Compressor Cooling Capacity with
HFC-245fa Relative to CFC-11.
01
w

2
a-
m
>
p
<
J
i
1.24
1.23
1.22
1.21 +
1.2
1.19
1.18
1.17
1.16
1.15
1.14
- Tc=40.6C Tc=46.1C -m- Tc=54.4C Tc=60C
-+-
0 2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 4. Compressor Electrical Input with
HFC-245fa Relative to CFC-11.
14

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-a- Tc=40.6C ~ Tc=46.1C > Tc=54.4C - Te=60C
0.98
0.92 i
0.88 -
0.86 -
2 4 6 8 10 12 14
EVAPORATING TEMPERATURE (C)
Figure 5, Compressor Energy Efficiency Ratio (EER) with
HFC-245ca Relative to CFC-11.
>H
U
Z
w
imm4
y
E
u,
UJ
06
O
x/i

CL,
s
O
o
w
>
H
<
J
 Tc=40.6C ~ Tc=46.1C * Tc=54.4C ~  Tc=60C
0.98
0.96
0.94
0.92
0.9
0.88
0.86 )	1	1	!	1	'	hi	1	i	!	1	1
0 2 4 6 8 10 12 14
EVAPORATING TEMPERATURE (C)
Figure 7. Compressor Isentroptc Energy Efficiency with
HFC-245ca Relative to CFC-11.
1.3
Tc=40.6C Tc=46. i C Tc=54.4C  Tc=60C
.25
1.2
15
1.1
4 6
EVAPORATING TEMPERATURE (C)
0
8
12
14
Figure 6. Compressor Energy Efficiency Ratio (EER)
with HFC-245fa Relative to CFC-11.
1.34
1.32
Tc=40.6C Tc=46.1C -m- Tc=54.4C Tc=60C
Pi 1.28
1.24 -
1.22 -
J 1.16
x
EVAPORATING TEMPERATURE (C)
Figure 8. Compressor Isentropic Energy Efficiency with
HFC-245fa Relative to CFC-11.

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g 1.04
w
>4
u
E 1.02 |
tx,
w
u
2 l
H
-Lj
. Tc=40.6C Tc=46.1C  Tc=54.4C  Tc=60C
t-
D 0.98
O
>
w 0.96 |
>

H
<
J 0.94
orf 0
oo
2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 9. Compressor Volumetric Efficiency with
HFC-245ca Relative to CFC-11.
14
o
1.22
H
1.2

1.18 -
O)

CO
3
1.16 -
EL*
CU

2
1.14 *
o
u

w
1.12 -
>
H
1.1 i
<
i

1.08 _
Tc=40.6C Tc=46.1C > Tc=54.4C Tc=60C
0 2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 11. Compression Ratio with HFC-245ca
Relative to CFC-11.
14
2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 10. Compressor Volumetric Efficiency with
HFC-24Sfa Relative to CFC-11.
14
Tc=40.6C -v- Tc=46.1C -m- Tc=54.4C Tc=60C
tuo
 1.1
O 1.08 I
o
p 1.06 -
2 4 6 8 10 12
EVAPORATING TEMPERATURE (C)
Figure 12. Compression Ratio with HFC-245fa
Relative to CFC-11.

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TECHNICAL REPORT DATA
N K MR L~ R T P" P~ 14 o (Please read Instructions on the reverse before completing)
1. REPORT NO. , 2.
EPA/600/A-97/012
3. REt
4. TITLE AND SUBTITLE
Calorimeter Performance Tests of HFC-245ca and
HFC-245fa as CFC-11 Replacements
S. REPORT DATE
6. PERFORMING ORGANIZATION COOE
7. AUTHOR(S)
G. Kazachki (A cur ex), C. Gage (EPA), E. Bayoglu (Acu-
rex), and R. Hendriks (EPA)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Acurex Environmental Corporation
P. 0. Box 13109
Research Triangle Park, North Carolina 27709
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, NC 27711
13. TYPE OF REPORT AND PERIOO COVERED
Published paper;6/94~6/96
14. SPONSORING AGENCY COOE
EPA/600/13
^supplementarynotes Project officer is Cynthia L< Gage> Mail Drop 63, 919/541-0590.
For presentation at International CFC and Halon Alternatives Conference, Washing-
ton, t>C, 10/21-23/96. g
16. abstractpaper gj.ves results of compressor calorimeter tests with hydrofluoro-
carbon (HFC)-245ca and HFC-245fa as alternatives for the refrigerant chlorofluoro-
carbon (CFC)-ll. Tests were performed in a semi-hermetic compressor at evapora-
ting temperatures from 1 to 13 C and condensing temperatures from 40 to 60 C. In
these ranges, the capacities and efficiencies of HFC~245ca were confirmed to be
lower than of CFC-11, while both capacities and efficiencies of HFC-245fa were sig-
nificantly higher. The higher-than-expected efficiencies and capacities for HFC-
245fa were a result of the higher compressor efficiencies. If the higher condensing
pressures for HFC-245fa could be found to be acceptable to low-pressure chiller
manufacturers, this refrigerant would be a viable alternative.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Refrigerants i
Halohydrocarbons
Calorimeters
Compressors
Pollution Prevention
Stationary Sources
CFC-11 Replacements
Hydrofluorocarbons
Chillers
Low-pressure Chillers
13	B
13A
07C
14	B
13 G
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport}
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)

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