Low-GWP Alternative Refrigerants Evaluation Program

Phase II - Testing Results at High-Ambient Temperature Conditions

Karim Amrane and Xudong Wang

Air-Conditioning, Heating, and Refrigeration Institute (AHRI)

International Roundtable Meeting onRisk Assessment Model for the use of low-GWP Refrigerants in High

Ambient Temperature CountriesOctober 3-4, 2017, Kuwait

Low-GWP AREP

Cooperative research & testing program to identify suitable alternatives to high GWP refrigerants

Evaluation of candidates strongly desired by OEM– assess research & development needs– accelerate industry’s response to environmental challenges– avoid duplicative work

The program is NOT to prioritize refrigerants, rather test and present objective results in a consistent manner

Phase I was completed at the end of 2013.– 38 refrigerants were evaluated in Phase I – AHRI published 40 test reports

Phase II started in 2014, testing concluded in 2016– 17 new refrigerants, high ambient testing– 34 additional reports were published

Final reports available to the public

Tested Low-GWP Refrigerants in Phase II

Baseline

Refrigerant

(Note 1) Composition (Mass%)

Classification

(Note 2)

GWP100

(Note 3)

R22/R-

407C

DR-93 (R-449C) R-32/R-125/R-1234yf/R-134a 20/20/31/29 A1 1251

N-20b R-32/R-125/R-134a/R-1234yf 13/13/31/43 A1 988

R-449B R-32/R-125/R-1234yf/R-134a 25.2/24.3/23.2/27.3 A1 1412

ARM-20b R-32/R-1234yf/R-152a 35/55/10 A2L 251

DR-3 (R-454C) R-32/R-1234yf 21.5/78.5 A2L 148

L-20a (R-444B) R-32/R-1234ze/R-152a 41.5/48.5/10 A2L 295

R404A

ARM-20b R-32/R-1234yf/R-152a 35/55/10 A2L 251

ARM-35 R-32/R-125/R-1234yf 12.5/61/26.5 A1 2220

DR-34 (R-452A) R-32/R-125/R-1234yf 11/59/30 A1 2140

N-40c (R-448A) R-32/R-125/R-134a/R-1234yf/R-1234ze 26/26/21/20/7 A1 1387

ARM-20a R-32/R-1234yf/R-152a 18/70/12 A2L 139

HDR110 R-32/R-1234yf/CO2 21.5/75.5/3 A2L 148

R410A

ARM-71a R-32/R-1234yf/R-1234ze(E) 68/26/6 A2L 460

DR-5A (R-454B) R-32/R-1234yf 68.9/31.1 A2L 466

DR-55 (R-452B) R-32/R-125/R-1234yf 67/7/26 A2L 698

HPR2A R-32/134a/1234ze(E) 76/6/18 A2L 600

L-41-1 (R-446A) R-32/R-1234ze/Butane 68/29/3 A2L 461

L-41-2 (R-447A) R-32/R-1234ze/R-125 68/28.5/3.5 A2L 583

Notes:

1. Refrigerants bolded were tested under high ambient conditions.

2. Refrigerants’ classifications or intended classifications according to the ASHRAE Standard 34 (ASHRAE, 2013).

3. GWP values are calculated based on IPCC AR-4 100 year.

Refrigerant Safety Classification

A2L safety group classification used by several refrigerant designation standards:

ASHRAE Standard 34

ISO 817

from: ASHRAE Standard 34-2010

Overview of High Ambient Testing

Tests cover the following products

– Air-conditioners (air-source packaged, unitary, mini-split, and air-to-water chiller) (10)

– Commercial ice machine(1)

Testing includes

– System drop-in test

• only minor modifications are allowed

– System “soft-optimization” test

• systems are modified for the alternative refrigerants using standard production line components

Low-GWP AREP Phase II HAT Matrix

Unit No. Equipment TypeBaseline

RefrigerantRefrigerants Tested Test type

Test StandardAREP Report No.

1 3-ton air source, split R-410A R-32 soft-optimization AHRI Standard 210/240 42 [5]

23-ton air source, split R-410A ARM-71a, DR-5A,

HPR2A, L-41-1, L-41-2

drop-in AHRI Standard 210/240 52 [6]

3 3-ton air source, split R-410A R-32, DR-5A, L-41-2 drop-in AHRI Standard 210/240 54 [7]

45-ton air source, rooftop

packaged unit

R-410A R-32, ARM-71a, DR-5A,

DR-55, HPR2A, L-41-2

drop-in AHRI Standard 210/240 47 and 53 [8, 9]

56-ton air source, rooftop

packaged unit

R-410A R-32 soft-optimization AHRI Standard 340/360 55 [10]

64-ton air source, rooftop

packaged unit

R-410A R-32, DR-5A, DR-55 soft-optimization AHRI Standard 210/240 56 [11]

72.5-ton air source, rooftop

packaged unit

R-22,

R410A

R-32 soft-optimization AHRI Standard 210/240 57 [12]

81.5-ton air source, mini-split R-410A R-32, ARM-71a, DR-55,

HPR2A, L-41-2

soft-optimization AHRI Standard 210/240 62 [13]

91.5-ton air source, mini-split R-22 N-20b, DR-3, ARM-20b,

L-20a, DR-93, R-290

soft-optimization AHRI Standard 210/240 62 [13]

102-ton air-to-water chiller R-410A R-32, DR-5A, L-41-1, L-

41-2

drop-in Tester defined

conditions

46 [14])

11

split system air-cooled

commercial ice machine

R404A ARM-20b, N-40c drop-in AHRI Standard 810 and

ASHRAE Standard 29

45 [15]

Air Conditioners: Standard Rating Condition

Air Conditioners: High Ambient Condition

Compressor Discharge Temperature

Refrigerant Charge Quantities

Ice Makers: High Ambient Conditions

Need to understand the results

When comparing drop-in test results, carefully review whether charge quantity, expansion device, and/or compressor speed were adjusted.

Results may vary significantly based on the criteria used to make adjustments.

– Charge optimization may target maximum capacity, or maximum efficiency (either full load or part load seasonal value), or neither (such as matching a target subcooling value).

– Compressor speed adjustment accommodates differences in volumetric capacity of each refrigerant.

Test VariationsUnit

No. Expansion Valve Lubricant Compressor Charging procedure

Unit-1

4-ton TXV for R410A

and 3-ton TXV for

R32

Prototype

POE for R-32 same

charge was adjusted to match superheat and

subcooling

Unit-2 adjustable TXV same POE same

TXV was used to adjust superheat and

charge level was adjusted to match subcooling.

Unit-3 same TXV same POE same

use same charge initially, then R32 charge was

optimized to match subcooling

Unit-4

adjustable stem was

placed on the

expansion valve same POE same

charge was adjusted to match the subcooling

at the “B” test. For DR-55 only: match the

superheat and subcooling at the “A” condition.

Unit-5

6.5-ton TXV for

R410A and 4.5-ton

TXV for R32

Prototype

POE for R-32

Prototype

compressor for R-32

(1.7% bigger

displacement

volume)

charge was adjusted to match subcooling and

superheat

Unit-6 adjustable TXV same POE

speed varies to

match capacity

(410A and DR55 at

60Hz, DR5A at

61Hz, R32 at 55Hz)

the optimum charge was selected to maximize

unit efficiency at “A” condition while also

matching the subcooling

Unit-7 same TXV same POE same

charge was reduced to reach minimum charge

with subcooling ranging 3-6K.

Test Results Summary

Summary

Several promising low GWP refrigerants exist for high ambient conditions.

The results should not be viewed as universally applicable and need to be interpreted carefully.

Need to focus on soft-optimized testing in the future.

Full optimization will likely improve the performance but will be done by OEMs.

Final reports available to the public

– AHRI web site: Home page > Resources > Research

– http://www.ahrinet.org/research.aspx

AHRI Low-GWP AREP-Phase II

Final reports available to the public

– AHRI web site: Home page > Resources > Research > AHRI Low-GWP Alternative Refrigerants Evaluation

– http://www.ahrinet.org/site/514/Resources/Research/AHRI-Low-GWP-Alternative-Refrigerants-Evaluation

AHRI staff contact information:Karim Amrane Xudong Wang

kamrane@ahrinet.org xwang@ahrinet.org

Tel: 703-600-0307 Tel: 703-600-0305

Thank you for your attention!