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

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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.

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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.