Use of R32 refrigerant in HVAC-R equipment

Comparison with refrigerants R22 and R410A

Hrvoje Krapani, Daikin Airconditioning Central Europe

47. Meunarodni kongres i izloba o KGH, Beograd, 30.112.12.201647th International HVAC&R Congress and Exhibition, Belgrade, Nov.30Dec.2 2016

47. Meunarodni kongres i izloba o KGH, Beograd, 30.112.12.201647th International HVAC&R Congress and Exhibition, Belgrade, Nov.30Dec.2 2016

What is HFC32 (R32) Benefits of R32 Toxicity & Flammability classification Main differences between R32, R410A & R22 Guidelines for installation/service works

Transport Room size limits Brazing Pressure Refrigerant charging & recovery

Tools Summary Conclusion

Outline/Agenda

What is HFC32 (R32)

HFC32 = R32 = difluoromethane, a single component HFC refrigerant

Known as a component of the blend refrigerant R410A (=50%R32+50%R125)

Already used in millions of air conditioners/ heat pumps in many parts of the world including in high ambient temperature zones

SNAP approved for Packaged Terminal air conditioners & heat pumps

Refrigerants ODP GWP(IPCC4)Flammability

(ISO817)

R320 675 2L

R220.055 1810 1

R410A

0 2088 1

ClC

H

FF

CHH

F

F

CHH

F

F

CC

F FF

FFH

50% R32

50% R125

3

Benefits of R32R32 is a refrigerant that addresses a range of environmental, safety and economic considerations:

Zero Ozone depletion potential (ODP)

Lower Global Warming Potential (GWP) about one third of R410A

R32 allows for reduced refrigerant charge, compact design and high energy efficiency

Easier to charge, recover and reuse because it is not a blend

Safe to use in many applications because it is an A2L classified refrigerant (low toxicity and lower flammability)

The potential global warming impact (GWP x kg) can be up to 75% less than that of R410A. Energy efficiency can also be improved by 5-10% depending on models.

Global Warming Potential(GWP)

Charge (kg) Global Warming Impact (GWPxkg)

Up to 75% lower global warming impact than R410A

4

New oils already available whichare optimal for both R32 & R410A

Previously used oils for R410A are not suitable for R32

No issue in most conditions(*)

(*) With R32, In very low ambient heating condition, discharge temperature may need to be controlled, e.g. by wet suction control

Main differences between R32, R410A & R22

5

R32 belongs to the ISO817 toxicity class A (low toxicity), same class as R410A and R22.

6

Refrigerant ATEL (% in air)Higher value is safer

ISO817ASHRAE34

Toxicity class

R32 22% A

R410A 17% A

R22 5.9% A

ATEL = Acute Toxicity Exposure Limit. Higher value is safer.

R32 toxicity classification

Flammability classification of R32

Standards Safety data sheets, cylinder labels

Code ISO817 GHS (UN Globally Harmonised System of Classification and Labelling of Chemicals) R32

Flammability Classification

Class 2LLower flammable refrigerant

Flammable GasCategory 1

SymbolIEC60335-2-40

5th edition

Criteria

LFL greater than 3.5% by volume* and Heat of Combustion less than 19MJ/kg and Burning Velocity less than 10cm/s

Gases, which at 20C and a standard pressure of 101.3kPa : (a) Are ignitable when in a mixture of 13% or less by

volume in air; or(b) Have a flammable range with air of at least 12

percentage points regardless of the lower flammable limit

DangerExtremely

flammable gas

* When tested in air at 23C and if no flame propagation is detected then tested at 60C & 101.3kPa

R32 flammability characteristics

Lower flammable limit LFL 14,5 % v/v

Upper flammable limit UFL 31% v/v

Heat of Combustion HoC 9,5 MJ/kg

Burning Velocity BV 6,7 cm/s

Minimum Ignition Energy MIE > 15-100 mJ

MIE of R32 varies depending on contact size / spacing and test apparatus. This is typical for difficult to ignite gases. Ammonia exhibits similar variations

7

Guidelines for installation/service- Transport -

The installer/service van Permanent ventilation required (Note : R32 is heavier than air

so outlet should be at the bottom) No smoking, no ignition sources or hot surfaces Follow the instructions for transport of the cylinders and

equipment Check local and trans-border transport regulations.

Remark: Similar precautions are already required for transporting acetylenefor brazing.

8

Charge/room size limitations

Charge limits for R32 installations based on EN60335-2-40 5th edition (depends on location of indoor unit). There are no room size limitations for refrigerant charges below 1.23 kg.

9

Amin = 2.5 x LFL5/4 x h0M 2

Amin = minimum room area (m)M = refrigerant charge (kg)h0 = height of leakLFL = Lower Flammability Limit in kg/m

Formula for minimum floor area for given flammable refrigerant charge

Chart1

1.2281.2281.228

1.2283.97452889663.251887279

1.28256163924.70272601043.8476849176

1.32757742244.86778388223.9827322673

1.53295436445.62083266954.5988630933

1.71389508266.28428196965.1416852479

1.87747799596.8840859855.6324339877

2.02790800977.43566270246.0837240292

2.16792485277.94905779316.503774558

2.29943154667.9826.8982946399

2.42381367037.9827.271441011

2.54211722387.9827.6263516713

2.65515484497.9827.9654645346

2.76357278197.9827.982

2.86789501067.9827.982

2.9685533627.9827.982

3.06590872887.9827.982

3.16026638197.9827.982

3.2518872797.9827.982

3.34099657987.9827.982

3.42779016537.9827.982

3.51243970597.9827.982

3.5950966557.9827.982

3.67589543237.9827.982

3.75495599187.9827.982

3.83238591117.9827.982

3.90828210887.9827.982

3.98273226737.9827.982

4.05581601957.9827.982

4.12760594717.9827.982

4.19816842517.9827.982

4.267564347.9827.982

4.33584970537.9827.982

4.40307619047.9827.982

4.4692915787.9827.982

4.53454016197.9827.982

4.59886309337.9827.982

4.66229868437.9827.982

4.7248826757.9827.982

4.78664846877.9827.982

4.84762734077.9827.982

4.90784862297.9827.982

4.96733986927.9827.982

5.02612700267.9827.982

5.08423444757.9827.982

5.14168524797.9827.982

5.19850117437.9827.982

5.25470282037.9827.982

5.31030968977.9827.982

5.36534027557.9827.982

5.41981213177.9827.982

ceiling mounted

floor mounted

wall mounted

GG.2 @ 0,6m

GG.2 @2,2m

GG.2 @ 1,8m

Room Area (m)

allowed charge (kg)

Refrigerants values

R1234yfR32R290R600aR152R410AR717

LFL (kg/m3)0.2990.3070.0380.0380.1300.116

Practical limit (kg/m3)0.0600.0610.0080.0110.0270.4400.000

h (m) (room height)2.5002.5002.5002.5002.5002.5002.500

ATEL/ODLNA0.3870.000

RCL (kg/m3)0.0600.0610.3900.390

QLMV (kg/m3)0.0620.0630.4200.420

QLAV (kg/m3)0.1500.1600.4200.420

Necessary charge

necessary charge/kW

refrigerant typecapacity (kW)capacity (kW)

3.501.00

chargeR410A1.200.34

R320.840.24

R2900.370.11

R12341.320.38

IEC proposal

1.84215.96479.821.8421.8420000

1.84215.96479.821.8423.9745288966103.3771.5754

1.84215.96479.821.8424.7027260104144.72782.2055.6

1.84215.96479.821.8424.8677838822155.06552.36256

1.84215.96479.821.8425.6208326695206.7543.158

1.84215.96479.821.8426.2842819696258.44253.937510

1.84215.96479.821.87747799596.8840859853010.1314.72512

1.84215.96479.822.02790800977.43566270243511.81955.512514

1.84215.96479.822.16792485277.94905779314013.5086.316

1.84215.96479.822.29943154668.43124900434515.19657.087518

1.84215.96479.822.42381367038.88731679125016.8857.87520

1.84215.96479.822.54211722389.32109648715518.57358.662522

1.84215.96479.822.65515484499.73556776456020.2629.4524

1.84215.96479.822.763572781910.13310020046521.950510.237526

1.84215.96479.822.867895010610.51561503897023.63911.02528

1.84215.96479.822.96855336210.88469566057525.327511.812530

1.84215.96479.823.065908728811.24166533918027.01612.632

1.84215.96479.823.160266381911.58764340028528.704513.387534

1.84215.96479.823.25188727911.92358668979030.39314.17536

1.84215.96479.823.340996579812.25032079269532.081514.962538

1.84215.96479.823.427790165312.568563939310033.7715.7540

1.84215.96479.823.512439705912.878945588410535.458516.537542

1.84215.96479.823.59509665513.182021068311037.14717.32544

1.84215.96479.823.675895432313.478283251911538.835518.112546

1.84215.96479.823.754955991813.7681719712040.52418.948

1.84215.96479.823.832385911114.052081673912542.212519.687550

1.84215.96479.823.908282108814.330367732313043.90120.47552

1.84215.96479.823.982732267314.603351646713545.589521.262554

1.84215.96479.824.055816019514.871325404714047.27822.0556

1.84215.96479.824.127605947115.134555139414548.966522.837558

1.84215.96479.824.198168425115.393284225415050.65523.62560

1.84215.96479.824.2675643415.647735913515552.343524.412562

1.84215.96479.824.335849705315.898115586216054.03225.264

1.84215.96479.824.403076190415.96416555.720525.987566

1.84215.96479.824.46929157815.96417057.40926.77568

1.84215.96479.824.534540161915.96417559.097527.562570

1.84215.96479.824.598863093315.96418060.78628.3572

1.84215.96479.824.662298684315.96418562.474529.137574

1.84215.96479.824.72488267515.96419064.16329.92576

1.84215.96479.824.786648468715.96419565.851530.712578

1.84215.96479.824.847627340715.96420067.5431.579.82

1.84215.96479.824.907848622915.96420569.228532.287579.82

1.84215.96479.824.967339869215.96421070.91733.07579.82

1.84215.96479.825.026127002615.96421572.605533.862579.82

1.84215.96479.825.084234447515.96422074.29434.6579.82

1.84215.96479.825.141685247915.96422575.982535.437579.82

1.84215.96479.825.198501174315.96423077.67136.22579.82

1.84215.96479.825.254702820315.96423579.359537.012579.82

1.84215.96479.825.310309689715.96424079.8237.879.82

1.84215.96479.825.365340275515.96424579.8238.587579.82

1.84215.96479.825.419812131715.96425079.8239.37579.82

m3*2

m2*2

m1*1,5

GG.2 @ 0,6m

GG.2 @ 2,2m

QLMV

UNV.

QLAV

m1*1,5

m2*2

m3*2

GG.2 @ 0,6m

GG.2 @2,2m

unv. L2T

QLMV

QLAV

Room (m)

charge (kg)

IEC 5th edition

1.2281.2281.228

1.2283.97452889663.251887279

1.28256163924.70272601043.8476849176

1.32757742244.86778388223.9827322673

1.53295436445.62083266954.5988630933

1.71389508266.28428196965.1416852479

1.87747799596.8840859855.6324339877

2.02790800977.43566270246.0837240292

2.16792485277.94905779316.503774558

2.29943154667.9826.8982946399

2.42381367037.9827.271441011

2.54211722387.9827.6263516713

2.65515484497.9827.9654645346

2.76357278197.9827.982

2.86789501067.9827.982

2.9685533627.9827.982

3.06590872887.9827.982

3.16026638197.9827.982

3.2518872797.9827.982

3.34099657987.9827.982

3.42779016537.9827.982

3.51243970597.9827.982

3.5950966557.9827.982

3.67589543237.9827.982

3.75495599187.9827.982

3.83238591117.9827.982

3.90828210887.9827.982

3.98273226737.9827.982

4.05581601957.9827.982

4.12760594717.9827.982

4.19816842517.9827.982

4.267564347.9827.982

4.33584970537.9827.982

4.40307619047.9827.982

4.4692915787.9827.982

4.53454016197.9827.982

4.59886309337.9827.982

4.66229868437.9827.982

4.7248826757.9827.982

4.78664846877.9827.982

4.84762734077.9827.982

4.90784862297.9827.982

4.96733986927.9827.982

5.02612700267.9827.982

5.08423444757.9827.982

5.14168524797.9827.982

5.19850117437.9827.982

5.25470282037.9827.982

5.31030968977.9827.982

5.36534027557.9827.982

5.41981213177.9827.982

ceiling mounted

floor mounted

wall mounted

GG.2 @ 0,6m

GG.2 @2,2m

GG.2 @ 1,8m

Room Area (m)

allowed charge (kg)

R32

EN378 (2008)EN 378 (2014)IEC proposal 2014IEC proposal 2015

class Aclass Bclass Cclass Aclass Bclass Cclass Aclass A

A(m2)V (M3)4 x LFL38 x LFL132 x LFLhuman comfortC.3 --- h0 = 0,6mhuman comfortC.3 --- h0 = 2,2mother systems: PLXRV

Basic rules for refrigerant pipes-- Dry, clean , tight --

10

Brazing

As per common HFC or HCFC refrigerants such as R410A & R22, R32 will decompose and release toxic substances if heated to high temperatures over 570C.

To avoid the possibility of this occurring during brazing, the system should be purged with dry nitrogen to ensure that there is no residual refrigerant present.

The risk of toxic by-products when R32 comes in contact with a flame or very hot surface is the same risk that has existed for over 40 years with R22.

Same procedures as for R410A or R22

11

Pressure

Pressure graph for R32 is similar to R410A

12

Charging & Recovery

Because it is not a blend, R32 can be charged in liquid or gas phase (as was the case for R22)

R410A needs to be charged in liquid state. Adding R410A in gas form may cause the refrigerant composition to change, preventing normal operation

R32 is also easier to recover, recycle or reclaim compared to blend refrigerants

13

14

Tools

Tool R32 R410A R22

Gauge manifold

Charge hose

Scale

Pipe bender

Pipe cutter

Flaring tool

Torque wrench

Cylinder thread adaptor

Vacuum pump

Recovery pump

Electr. Leak detector

Refrigerant recovery cylinder

Slightly different scale for HFC32 and R410A so check with tool supplier if manifold is shareable

Common

R22 type can be used by changing the work process

Some flare nuts widths are different, others can be shared

Common

Common

Check with tool supplier if shareable

Common

Common

Common

Common

Check with tool supplier if shareable

Not applicableDepends on the cylinder some have different thread for flammable gases

Torch type models CANNOT be used.

Installation/service - Dos

Ventilate the area if brazingVentilate the area in the event of any refrigerant leakPressure test the system to 4.0MPaEvacuate the system to a minimum of 500microns Signpost and restrict access to the area if brazing or if a leak occursHave a fire extinguisher at handRemove any potential source of ignition

15

Summary

Installation/service - Donts

Charge R32 into systems other than those designed for R32

Charge an R32 system with oil other than that specified by the manufacturer

Use a reclaim cylinder other than an R32 reclaim cylinder

Install pipe work with diameters that are not specified for that model

Forget to add additional refrigerant if required

16

Summary

Conclusions

Installation/service practices for R32 are :

Similar to R410A : similar pressure, shareable tools Similar to R410A and R22 : basic rules for piping & brazing Different from R22 : : higher pressure, different oil type Different from R410A and R22 : because R32 is flammable, specific guidance

and regulations need to be followed (transport, room size limits, work instructions). Always

follow guidance from gas and equipment providers and the local regulations.

17

HVAC-R industry was and is looking for the answer on the pressure coming from efforts to reduce GWP in the world and EU.

Some producers decided to go with R32 refrigerant, since it is perceived as the best solution in given circumstances, taking lots of aspects into consideration like: reduction of CO2 technical utilisation of available technologies, Safety during installation and in use economic component to keep the competitiveness and prices to the consumers, availability of the refrigerant,

Having all this in mind R32 is optimal (and preferable) choice as the key refrigerant for the next period when we talk about airconditioners and heat pumps.

18

Conclusions

Use of R32 refrigerant in HVAC-R equipmentSlide Number 2What is HFC32 (R32)Benefits of R32Main differences between R32, R410A & R22Slide Number 6Flammability classification of R32Guidelines for installation/service - Transport - Charge/room size limitationsBasic rules for refrigerant pipesBrazingPressureCharging & RecoverySlide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19