AHRI’sResearchonRooftopPackagedHeatPumps

XudongWangandKarimAmraneAir-Conditioning,Heating,andRefrigerationInstitute(AHRI)

Overview

Ø IntroductionØ LowGWPrefrigerantperformancetestingØ RiskassessmentonrooftopunitsusingA2LrefrigerantsØ Industryupdateonflammablerefrigerantresearch(outsidethepapercontent)

Introduction

Ø Air-Conditioning,Heating,andRefrigerationInstitute(AHRI)– Representingover300HVACRandwaterheatingmanufacturerswithintheglobalindustry

– Administersrigorouscertificationprograms– Establishesinternationalstandards– Representstheindustrydomestically&globally

Low-GWPAREPIntroduction

Ø Cooperativeresearch&testingprogramtoidentifysuitablealternativestohighGWPrefrigerants

Ø EvaluationofcandidatesstronglydesiredbyOEMs– assessresearch&developmentneeds– accelerateindustry’sresponsetoenvironmentalchallenges– avoidduplicativework

Ø TheprogramisNOTtoprioritizerefrigerants,rathertestandpresentobjectiveresultsinaconsistentmanner

Ø PhaseIItestingwascompletedin2016– newrefrigerants– highambienttestingupto125°F(52°C)

Ø Finalreportsavailabletothepublic

SummaryofTestedHeatPumpsinPhaseIIUnitNo.

EquipmentType RefrigerantsTested Testtype TestStandard

1 3-tonairsource,splitsystem ARM-71a,DR-5A,HPR2A,L-41-1,L-41-2(R410Abaseline)

drop-in AHRIStandard210/240

2 3-tonairsource,splitsystem R-32,DR-5A(R410Abaseline)

drop-in AHRIStandard210/240

AHRIStandard210/2403 4-tonairsource,rooftop unit R-32,DR-5A,DR-55(R410Abaseline)

soft-optimization

4 1-tonwater-to-waterheatpump

R-32,L-41-1,L-41-2(R410Abaseline)

drop-in ISOStandard13256-2andENStandard14511-2

5 1-ton,single packagedverticalheatpump(SPVH)

R-32(R410Abaseline)

drop-in AHRIStandard390

6 3-tonwater-toair heatpump R-32,DR-5A,DR-55,L-41-2(R410Abaseline)

drop-inandsoftoptimization

ISOStandard13256-1

7 4.5tonair-to-waterheatpump DR-3,L-20a,R-290(R407Cbaseline)

drop-in ENStandards14511and14825

TestedLow-GWPRefrigerantsinPhaseII

Baseline Refrigerant Composition (Mass%)Classification

(Note1)GWP100(Note2)

R-407CR-290 R-290 100 A3 <5DR-3 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

R410A

R32 R-32 100 A2L 675ARM-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 466DR-55(R-452B) R-32/R-125/R-1234yf 67/7/26 A2L 698

HPR2A R-32/134a/1234ze(E) 76/6/18 A2L 600L-41-1(R-446A) R-32/R-1234ze/Butane 68/29/3 A2L 461L-41-2(R-447A) R-32/R-1234ze/R-125 68/28.5/3.5 A2L 583

Notes:1. Refrigerants’ classifications or intended classifications according to the ASHRAE Standard 34 [3].2. GWP values are calculated based on IPCC AR-4 100 year.

TestTypes

Ø Drop-inTest– onlyminormodificationsareallowed,e.g.adjustingchargeorsuperheatsetting.

Ø System“soft-optimization”test– systemsaremodifiedforthealternativerefrigerantsusingstandardproductionline

components– UnitNo.3:

• thecompressorwasfittedwithavariablefrequencydrive(R-410AandDR-55at60Hz,R-32at55HzandDR-5Aat61Hztoachieveequalcapacityatstandardratingconditionforcoolingapplication.)

– UnitNo.6:• TXVwasre-sizedfrom3-tonto4-ton.

HeatPumpsHeatingPerformance

Needtounderstandtheresults

Ø Whencomparingtestresults,carefullyreviewwhetherchargequantity,expansiondevice,and/orcompressorspeedwereadjusted.

Ø Resultsmayvarysignificantlybasedonthecriteriausedtomakeadjustments.– Chargeoptimizationmaytargetmaximumcapacity,ormaximumefficiency(eitherfull

loadorpartloadseasonalvalue),orneither(suchasmatchingatargetsubcoolingvalue).

– Compressorspeedadjustmentaccommodatesdifferencesinvolumetriccapacityofeachrefrigerant.

RiskAssessmentofA2LRefrigerantsinRooftopUnitsØ AHRI’scontractorNavigantconductedariskassessmentforsixscenarios,

includingthreesizesofrooftopunitsusingtwodifferentlow-GWPrefrigerants.

Scenario Refrigerant Equipment Building Description

A R-3215TonRoof Commercial

Kitchen

Two-circuitRTU(5Tand10T)mountedontheroofabovetheconditioned space,whichconsistsonlyofthekitchen.B R-1234yf

C R-3225TonRoof Office

Two-circuitRTU(12.5T each)mountedontheroofabovetheoffice;returnandsupplyductsservemultipleoffices.D R-1234yf

E R-32

5TonGround Office

Single-circuitRTUmountedonthegroundadjacenttotheoffice;multiplereturn ductingconfigurationsareanalyzed,includingdirectlyductedhorizontallyandductedverticallyupintotheroof.F R-1234yf

RefrigerantDispersionModeling

# Did a substantial plume accumulate with a flammable concentration?

Inside the RTU/Ventilation

In Conditioned Space Outside the RTU

1 2 3 4 5 6 7 8 9 10 Legend:

- Substantial Flammable Plume - Small Flammable Plume - No Flammable Plume

RefrigerantDispersionModeling

# Did a substantial plume accumulate with a flammable concentration?

Inside the RTU/Ventilation

In Conditioned Space Outside the RTU

1 2 3 4 5 6 7 8 9 10 Legend:

- Substantial Flammable Plume - Small Flammable Plume - No Flammable Plume

FaultTreeAnalysis

(Chartsource:NavigantreportingslidestoAHRI)

PotentialIgnitionSources

(Tablesource:NavigantreportingslidestoAHRI)

AnnualIgnitionRisk

(Tablesource:NavigantreportingslidestoAHRI)

CommonSafetyHazardRisk Risk(unit/year)

Fatalinjuryriskforworkerinthemining,quarrying,andoilandgasextractionindustry

1.2E-4

Occupantfatalityriskintrafficcrash(perpersoninU.S.) 8.5E-5

FatalinjuryriskonthejobforemployedpeopleintheU.S. 3.3E-5

Non-occupantfatalityriskintrafficcrash(perpersoninU.S.) 1.8E-5

Injuryriskforparkattendeeonamusementparkride 4.7E-6

Summary

ØHeatpumptestinginLow-GWPAREP– alternativecandidatesdemonstratedcomparableperformance.

– furtherperformanceimprovementispossiblethroughfulloptimization.

– Theresultsshouldnotbeviewedasuniversallyapplicableandneedtobeinterpretedcarefully.

Ø Rooftopunitriskassessment– theignitionrisksoftheA2LrefrigerantsinRTUsaresignificantlylowerthancommonhazardevents.

IndustryUpdateonFlammableRefrigerantResearch

Ø Acollaboratedresearchprogramissupportedby– AHRI($1million)– ASHRAE($1.3million)– CaliforniaAirResourceBoard($0.3million)– USDepartmentofEnergy($3million)

Ø Theobjectiveisto– producepubliclyavailabletechnicalresultstosupportcodeand

standardactivitiesrelatedtotheuseofflammablerefrigerants.• Ensureatimelycompletionofrelevantstandardrevision.

Summer2017:draft

ASHRAE15completedforPPR

Endof2017:publicationoftheupdatedASHRAE15including2Lrefrigerants

Jan2018:2021IMC:changeproposalsaredue

AHRTI&ASHRAEResearchto

supportthe15revision

IdentifiedanddevelopedhighpriorityprojectsØ AHRTIConducting:

– AHRTI-9007:BenchmarkingRiskbyRealLifeLeaksandIgnitionsTesting– AHRTI-9008:InvestigationofHotsurfaceIgnitionTemperature(HSIT)forA2L

Refrigerants– AHRTI-9009:LeakDetectionofA2LRefrigerantsinHVACREquipment

Ø ASHRAEconducting:– ASHRAE-1806:FlammableRefrigerantsPost-IgnitionSimulationandRiskAssessment

Update– ASHRAE-1807:GuidelinesforFlammableRefrigerantHandling,Transporting,Storing

andEquipmentServicing,InstallationandDismantling– ASHRAE-1808:ServicingandInstallingEquipmentusingFlammableRefrigerants:

AssessmentofField-madeMechanicalJointsØ DOEfunding:

– ORNL:InvestigatetheproperbasisforsettingchargelimitsofA2L,A2,andA3forvarioustypesofproducts

– NIST:Modelingtoolsforlow-GWPrefrigerantblendsflammability

CommercialkitchenwithrooftopAC

Contact

KarimAmrane,XudongWangEmail:kamrane@ahrinet.org,xwang@ahrinet.org

Tel:703-600-0305

AHRIResearchReportscanbedownloadedattheAHRIwebsite:www.ahrinet.org

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Thankyouforyourattention!

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