Mohammad Khawaldeh
Director, Unitary & Applied Product Units
System Soft-optimization Tests ofRefrigerant R-32 in a 6-ton Rooftop
Packaged Air-Conditioner
Presentation Outline
Objectives
Challenges
Base Unit Information vs. Optimization of R-32
Test Lab and Test Setup
Instrumentation
Test Conditions
Test Results
Conclusion
2/2/2016 2
Objectives
Evaluate the performance of the Low GWP alternative R-32 to replace R-410A refrigerant at high ambient conditions.
Create a comparison between R-410A and R-32 refrigerants in terms of Capacity & EER at high ambient conditions.
Build experience on R-32 system at high ambient conditions, to understand the required modifications on the existing R-410A system.
2/2/2016 3
Challenges
Material availability, such as, Refrigerant, TXV & Compressor.
Safety measures for mild flammable refrigerant.
Testing condition stability at extreme high ambient.
Cooling capacity decreases due to higher condensing temperature.
Refrigerant and Oil decomposition at high discharge temperature.
Viscosity of the oil decreases at high ambient.
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Base Unit - Equipment Description
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PTH006
Rooftop Packaged Air Conditioner
Single Refrigerant Circuit
Scroll Compressor
Thermostatic Expansion Valve
R-410A design
Base Unit Information vs. Optimization of R-32
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R-410A R-32
PTH006 Base Unit Information Optimization of R-32
Nominal Cooling
Capacity
71,848 BTU/HR 78,343 BTU/HR
Nominal Air Flow 2500 CFM 2500 CFM
Compressor ZP61K5E ZP61KCE (Sample)
Refrigerant Charge 295 Oz 260 Oz
Expansion Valve Size TGEL 6.5 TGEL 4.5
Lubrication POE Oil /42 Oz /96 cSt POE Oil /56 Oz/96 cSt
Super heat 11 ~15 ºF 11 ~15 ºF
Subcooling 15 ~17 º F 15 ~17 º F
Power Supply 460 V-3 ph-60 hz 460 V-3 ph-60 hz
Evaporator Coil Copper tube and aluminum fin, 8.0 ft² ,3/8" tubes, 3 rows, 14 FPI
Condenser Coil Copper tube and aluminum fin, 12.7 ft² ,3/8" tubes, 2 rows, 14 FPI
Test Laboratory - IKHTIBAR
Tests were held in Ikhtebar Lab – Saudi Arabia Founded in 2006.
It is the first independent laboratory for testing climate control solutions in the Middle East.
It was constructed by Intertek Testing Services (ITS) as per ASHRAE-37 standard.
Ikhtebar Lab has been accredited according to SASO/ISO17025 standard.
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Facility Application
Calorimetric Test Rooms (3 NO) Used for testing the capacities of consumer range of air conditioners
Psychrometric Test Rooms (3 NO) Tests Unitary range of air conditioning units up to 30 TR
Chiller Test Facility Measures the cooling capacity of chillers, up to 200 TR
Sound Lab Consists of two reverberant sound rooms to measure sound power levels of air
conditioners under load conditions and a hemi-anechoic facility to isolate and
analyze the unit sound sources
Reliability Test Facility Qualifies window and mini-split air conditioners to sustain the severe ambient
conditions by running rigorous tests of component cycling and durability
Test Setup
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INDOOR
ROOM
OUTDOOR
ROOM
T#1 Evaporator Inlet Temperature P#1 Compressor Suction Pressure
T#2 Evaporator Outlet Temperature P#2 Compressor Discharge Pressure
T#3 Compressor Suction Temperature P#3 Condenser Outlet Pressure
T#4 Compressor Discharge Temperature
T#5 Condenser Outlet Temperature
Total 5 Total 3
Temperature Data Locations Pressure Data Locations
Data Measurement Locations
* Evaporator Air
Inlet Temperature
* Condenser Air
Inlet Temperature
* Evaporator Air
Outlet Temperature
* Condenser Air
Outlet Temperature
* Evaporator Air Flow * Condenser Air Flow
Extra Measurements
Test Setup
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1. Maintain the indoor air conditions
2. Measure the evaporator air flow
1. Maintain the outdoor air
conditions
2. Measure the condenser air flow
Indoor Room Compressor ReadingOutdoor Room
1. Measure the suction and
discharge pressure
2. Measure the discharge
temperature
Test Conditions
TestIndoor Outdoor
OperationsDB (°F) WB (°F) DB (°F) WB (°F)
T1 80 67 95 75 Cooling Capacity & EER
T3 80 67 115 75 Cooling Capacity & EER
Hot Ambient 80 67 125 75 Cooling Capacity & EER
Extreme Ambient 80 67 130 75 Cooling Capacity & EER
Low Ambient – 1 80 67 81.5 NA IEER
Low Ambient – 2 80 67 68 NA IEER
Low Ambient – 3 80 67 65 NA IEER
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AHRI 340/360 Standard for All Ambient Conditions
Test Results
Test Results - Refrigerant Charge
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R-32 charge is 12% lower than R-410A charge
R410A 18.43
R32 16.25
-12 %
14
15
16
17
18
19
20
Refr
igera
nt
Charg
e (
Ib)
R410A 1.71
R32 2.29
+34 %
0
0.5
1
1.5
2
2.5
3
3.5
4
Lubricant
Charg
e (
Ib)
Test Results - Lubricant Charge
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R-32 lubricant has larger lubricant charge by 34% more than R-410A
R-32 prototype compressor has slightly lager displacement volume
than R-410A compressor (7.18 ft3/min Vs 7.06 ft3/min )
Test Results - Cooling Capacity
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R-32 has higher capacity by 12% (Avg.) than R-410A. At high ambient
condition, R-32 shows higher capacity (up to 16 %)
95 100 105 110 115 120 125 130
R410A 71848 70634 68217 65872 64706 61272 56472 54167
R32 78343 77619 75734 73936 71611 68378 65344 61467
+9% +10% +11% +12% +11% +12% +16%+13%
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
Coolin
g C
apacity (
Btu
/hr)
Ambient Temperature (ºF)
Test Results - Degradation on Cooling Capacity
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R410A has reduction in capacity by 10% at 115 ºF ambient and
25% at 130ºF ambient
-2% -5% -8% -10%-15%
-21%-25%
-1% -3% -6% -9%-13% -17%
-22%
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
95 100 105 110 115 120 125 130
Coolin
g C
apacity (
Btu
/hr)
Ambient Temperature (ºF)
R-410A Curve R-32 Curve
Test Results - Energy Efficiency Ratio
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R-32 has higher energy efficiency ratio by 5% (Avg.) than R-410A
At high ambient condition, R-32 shows higher EER (up to 10 %)
95 100 105 110 115 120 125 130
R410A 12.19 11.46 10.51 9.67 8.98 8.09 7.03 6.41
R32 12.44 11.77 10.92 10.16 9.37 8.51 7.73 6.90
+2%+3%
+4%+5%
+4%+5%
+10%+8%
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
EE
R (
Btu
/hr/
W)
Ambient Temperature (ºF)
Test Results - Integrated Energy Efficiency Ratio
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R410A has better integrated energy efficiency ratio (IEER)
by 4% than R32
R410A 14.38
R32 13.85
+4%
12
12.5
13
13.5
14
14.5
15
IEE
R
Test Results - Suction Pressure
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R-32 has suction pressure higher by +4 Psi (Avg.) than R-410A
95 100 105 110 115 120 125 130
R410A 139.3 142.5 143.4 144.4 145.1 145.8 147.5 148.7
R32 144.9 144.9 146.2 147.5 148.3 150.0 151.2 152.1
+6 +2+3
+3 +3+4
+4 +3
130.0
135.0
140.0
145.0
150.0
155.0
Suction P
ressure
( P
sig
)
Ambient Temperature (ºF)
Test Results - Discharge Pressure
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R-32 has discharge pressure higher by +26 Psi (Avg.) than R-410A
At 130 ºF ambient, R-32 discharge pressure is +32 Psi higher than
R-410A
95 100 105 110 115 120 125 130
R410A 403.1 422.1 454.3 476.7 504.9 533.7 567.9 599.4
R32 415.4 446.5 474.7 503.7 533.7 565.1 597.5 631.0
+12+24
+20 +27 +29 +31+30 +32
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
Dis
charg
e P
ressure
(P
sig
)
Ambient Temperature (ºF)
Test Results - Discharge Temperature
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R-32 has discharge temperature higher by +35 ºF (Avg.) than R-410A
At 130 ºF ambient, R-32 discharge temperature is +44 ºF higher than
R-410A
95 100 105 110 115 120 125 130
R410A 159.4 166.2 172.3 180.2 186.8 194.4 203.3 211.6
R32 188.2 196.9 205.5 213.9 223.2 232.0 241.8 255.9
+29 +31 +33 +34 +36 +38 +38 +44
0.0
50.0
100.0
150.0
200.0
250.0
300.0
Dis
charg
e T
em
pera
ture
( º
F)
Ambient Temperature (ºF)
Conclusions
R-32 refrigerant is compatible to the existing of R-410A system with minor modifications.
Unit has been tested up to 130 ºF ambient without any fault or tripping due to optimized condenser design.
R-32 has better performance and efficiency than R-410A at high ambient.
R-32 performance results may improve as the R-32compressor design is optimized.
R-32 systems need additional oil cooling or discharge Gas cooling system to reduce the high discharge temperature at high ambient conditions.
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Thank you.