Performance Test Study of Car Cooling System (Air
Conditioning/AC) Using Block and Elder Type Expansion Valve
Jhon Arnoldos Wabang, Edwin P. D. Hattu and Jufra D. J. Abanat
Statete Polytechnics of Kupang, Lasiana, Adisucipto Street, Kupang, Indonesia
Keywords: Air Cooling, Expansion Valve, Block Valve.
Abstract: Air cooling in cars is an absolute necessity in cars because it can provide comfort for drivers and passengers.
There are a series of main components to support the working system, namely the compressor, condenser,
filter drayer, expansion valve and evaporator. The five components that are of concern in this study are the
expansion valves because in all cooling systems there are different types of expansion valves, but have the
same function of these types of expansion valves, namely to lower the pressure and lower the temperature of
the system. The types of expansion valves in question are elbow type expansion valves (TXV) sensing and
box or block type expansion valves These two types of expansion valves were tested using the car's air
conditioning cooling system. The refrigerant material used is refrigerant (R134a. The results showed that the
performance of the expansion valve (TXV), Coeficient of Performance (COP) was 3.79, Refrigeration
Efficiency 64,45%, cooling capacity 3.26 kW, and refrigeration effect 160.06 kJ/kg. For valve block
Coeficient of Performance (COP) is 3.90, Refrigeration Efficiency 70.28%, cooling capacity 2.89 kW, and
refrigeration effect 115.75 kJ/kg.
1 INTRODUCTION
Technology to provide comfort for passengers in
driving is a necessary requirement in a vehicle.
Comfort in question is the need for cool air for
passengers. Coolness can be obtained with a
technology called air conditioning (Air Conditioning
/ AC) in cars. In this technology there is a series of
interrelated components of the system to produce cool
air while driving, therefore the use and application of
components that can work effectively and efficiently
continue to be researched in order to get an AC
working system that can provide comfort for users in
their daily activities (Handbook-Fundamentals,
2009); (Wardika, 2018).
In the cooling system (AC), there are a series of
main components to support the working system,
namely the compressor, condenser, filter drayer,
expansion valve and evaporator. The five components
that are of concern in this study are the block and
elbow type expansion valves, because in all cooling
systems there are different types of expansion valves,
but have the same function of these types of
expansion valves, namely to lower the pressure and
lower the temperature of the system. The types of
expansion valves in question are elbow-type (TXV)
sensing expansion valves and box or block-type
expansion valves (Muslih, 2020); (Jamaludin, 2018).
This type of expansion valve will be tested using
the car's air conditioning cooling system. The
refrigerant material used is refrigerant (R234a). The
basis for choosing this material is because the car air
conditioner compressor is only suitable for using
R134a (Wang et al., 2016).
The test model used is to vary the two types of
valves to determine the performance of the system in
the form of Coeficient of Performance (COP),
cooling capacity (Cooling Capacity), refrigeration
effect and system efficiency.
2 RESEARCH METHODOLOGY
The method used in this research is the experimental
method and it was conducted in the Refrigeration
Engineering laboratory, with the set up as figure 1.
The implementation of this research followed the
flow chart as shown below in fig.2. From this set up
of experiments, a system test is performed with steps
such as the following flow chart (Stubblefield et al.,
2009); (Prabakaran et al., 2021).
1052
Wabang, J., Hattu, E. and Abanat, J.
Performance Test Study of Car Cooling System (Air Conditioning/AC) Using Block and Elder Type Expansion Valve.
DOI: 10.5220/0012056700003575
In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 1052-1055
ISBN: 978-989-758-619-4; ISSN: 2975-8246
Copyright © 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

Figure 1: Set Up Experimental.
Figure 2: Flow Charts.
3 RESULT AND DISCUSSION
3.1 Result
This test is carried out on a cars AC with the
following specifications:
1. The mass of refrigerant = 250gr
2. Testing time = 100 Minutes
Based on the planned system design and the
research flow, the test results of the two valves can be
seen in the following table below :
Table 1: Test Results for Expansion Valve (TXV).
No
Time
(Men
ute)
Massa
Refrig
eran
(gr)
Temperature
(
0
C)
Low
Pres
sure
(Psi)
Eva
pora
tor
Con
dens
er
Env
oron
men
t
1
20
50
30,1
35
30,6
2
2
40
100
29,1
43,3
30,3
5
3
60
150
25,1
56,2
30,1
7
4
80
200
22,4
61,2
29,6
10
5
100
250
18,4
68
29,8
14
Figure 3: Graph of relationship between Mass, Pressure and
Evap. Temperaure.
Table 2: Test Results for Block Valve.
N
o
Time
Men
ute)
Mass
Refri
gerat
(gr)
Temperature (
0
C)
Low
Pres
sure
(Psi)
Eva
por
ator
Cond
enser
Env
iron
men
t
1
20
50
29,3
41,4
30,6
17
2
40
100
27,4
59,3
30,6
21
3
60
150
24,8
60,6
29,5
25
4
80
200
20,8
69,4
29,5
30
5
100
250
16,5
64,8
29,5
35
0
5
10
15
20
25
30
35
0
5
10
15
0 100 200 300
Evaporator Temp.
(
0
C)
Low Pressure
(Psi)
Mass Refrigerant
(gr)
Graph Relation Mass, Pressure dan
Temperature Evaporator
Mass vs Low Pressure
Performance Test Study of Car Cooling System (Air Conditioning/AC) Using Block and Elder Type Expansion Valve
1053

Figure 4: Graph of relationship between Mass, Pressure and
Evap. Temperaure.
3.2 Discussion
All of the test results in the table and graph above can
be calculated the performance of cars AC with R134a
refrigerant as follows:
3.2.1 Expansion Valve (TXV)
In this expansion valve, based on the test results in the
table 1 above, it appears that in the 100th minute with
a refrigerant mass of 250 g, the evaporator
temperature reaches a temperature of 18.40C at a low
pressure of 14 Psi.
Test result data through coolpack software are as
follows :
Figure 5: Graph of p-h diagram for Expansion Valve.
The graph in this figure shows the enthalpy values
as follows:
h
1
= 418,47 kJ/kg h
3
= 292,35kJ/kg
h
2
= 460,74 kJ/kg h
4
= 292,35kJ/kg
Refrigerator performance based on enthalpy
values are as follows:
1. Specific work by the Compressor (Q
w
).
42,27 kJ/kg
2. The heat is released by the condenser (q
k
)
168,39 kJ/kg
3. Refrigeration Effect (q
e
)
160,06 kJ/kg
4. Coeffisient Of Performance(COP)
a. COP
aktual
= 3,79
b. COP
carnot
= 5.88
5. Refrigeration Efficiency (η)
64,45%
6. Pressure Ratio :
5,79.
3.2.2 Block Valves
In block valves, based on the test results in table 2
above, it appears that in the 100th minute with a
refrigerant mass of 250 gr, the evaporator temperature
reaches a temperature of 14.10C at a low pressure of
35 Psi
Test result data through coolpack software are as
follows :
Figure 6: Graph of p-h diagram for Block Valve.
The graph in this figure shows the enthalpy values
as follows:
h
1
= 411,12 kJ/kg h
3
= 295,37 kJ/kg
h
2
= 440,78 kJ/kg h
4
= 295,37 kJ/kg
1. Specific work by the Compressor (Q
w
).
29,66 kJ/kg
2. The heat is released by the condenser (q
k
)
145,41 kJ/kg
3. Refrigeration Effect (q
e
)
115,75 kJ/kg
4. Coeffisient Of Performance(COP)
c. COP
aktual
= 3,90
d. COP
carnot
= 5,53
5. Refrigeration Efficiency (η)
70,28%
6. Pressure Ratio :
3,83.
0
5
10
15
20
25
30
35
0
10
20
30
40
0 100 200 300
Evaporator Temp.
(
0
C)
Low Pressure
(Psi)
Massa Refrigeran
(gr)
Graph Relation Mass, Pressure and
Evaporator Temp.
Mass vs Pressure Mass vs Evaporator Temp.
iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science
1054

4 CONCLUSIONS
Based on the results of data analysis, it can be
concluded as follows:
1. In expansion valve (TXV), Coeficient of
Performance (COP) was 3.79, Refrigeration
Efficiency 64.45%, pressure ratio 5,79 and
refrigeration effect 160.06 kJ/kg.
2. For valve block, Coeficient of Performance
(COP) is 3.90, Refrigeration Efficiency 70.28%,
pressure ratio 3,83 and refrigeration effect 115.75
kJ/kg.
3. The result of COP, efficiency and pressure ratio
of block valve is more than expansion valve.
ACKNOWLEDGEMENTS
The authors would like to thank State Politeknik of
Kupang for the financial support through the RUTIN
Research Programme. A thank you also goes to
Wilmar for their help to record the values of
performance of car cooling system based on variation
of expansion valve and block valve using manifold
gauge and electrical equipments.
REFERENCES
Handbook-Fundamentals, A. S. H. R. A. E. (2009).
American society of Heating. Refrigerating and Air-
Conditioning Engineers.
Muslih, N. (2020). Analysis of Air Conditioner (AC)
Performance Against Changes in Compressor Pressure
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ISSN : 2548-1878 (Online)
Wardika, W. (2018). Effect of Evaporator Blower Rotation
Speed on Car AC Performance, Journal of Applied
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Jamaludin. (2018). Design of an Air Condition (Ac) System
Simulator on a Sanden Type Car, Journal of
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Performance Test Study of Car Cooling System (Air Conditioning/AC) Using Block and Elder Type Expansion Valve
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