Impact of New Refrigerant Regulations on Postharvest Cooling

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Impact of New Refrigerant Regulations on Postharvest Cooling
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Baird, C.D.
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University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
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"Publication date: January 1996. Reviewed: April 1997."
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"Circular 1165"

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Circular1165 ImpactofNewRefrigerantRegulationsonPostharvest Cooling1 C.DirelleBaird&MichaelT.Talbot2Newregulationsandtaxesintendedtoprotectthe earth'satmosphereareincreasingthecostand reducingthesuppliesofrefrigerantsneededto operateyourrefrigerationsystems.Chlorofluorocarbons(CFCs),themostwidelyusedchemicalsfor refrigerationarebeingphasedoutinaneffortto decreasedamagetotheozonelayeraswellasreduce theglobalwarmingeffectofgassesreleasedintothe atmosphere.OZONEDEPLETINGREFRIGERANTSThefuroroverconventionalrefrigerantshasbeen causedbyconcernthatthesechemicalsdestroythe ozonelayer,theuppermostleveloftheearth's atmosphere.Ozonereflectsultraviolet(UV) radiation,whichcausesskincancerinhumansand candisruptthegrowthofmarineplantsandanimals. ThebadguysareCFCs(chlorofluorocarbons), includingR-12,R-11,R-115,whichdothemost damagetotheozonelayer.Theyareextremely stable,whichisgoodfromarefrigerationperspective, butbadbecausetheydonotbreakupuntiltheycome incontactwithhighintensitysolarradiationsome35 milesabovetheearth'ssurface.Whentheybreakup, chlorineatomsarereleasedwhichfractureozone molecules. Anothercategoryofrefrigerantswhichdamage theozonelayer,buttoamuchlesserextent,are HCFCs(hydrochlorofluorocarbons).Theybreakup muchfasterandatlowerlevelsintheatmosphere, comparedtoCFCs,sothatlesschlorinereachesthe outerozonelayer.IncludedinthisgroupareR-22 (usedinmostallresidentialandsmallcommercialair conditioningsystems),andagroupofnewrefrigerants (sometimesreferredtoaslowozonedepleting refrigerants)thatarebeingusedassubstitutesforthe CFCs.Theuseoftheserefrigerantswillreducethe damagingeffectontheozonelayer,butwill eventuallyhavetobereplacedwithrefrigerants havingazerodepletionrate. Severalworldwideefforts,startingwiththe1987 MontrealProtocol,aremovingtoreduceand eliminateCFCsandHCFCs.Baseduponthese initiatives,theUSCleanAirActhasmandatedthat nomoreCFCswillbemanufacturedafterDecember 1995andthatHCFCswillbeginreductionin1996 andbecompletelyphasedoutby2030.Italso imposesstifffinesforventingCFCsandHCFCsinto theatmosphere.TheonlyCFCsthatwillbeavailable beginningin1996willbethosethatarerecoveredand remanufactured.Recoveryandrecyclingequipment arebecomingbigbusinesses. Agroupofrefrigerantsknownasazeotropesare mixturesofhalocarbons(CFCs,HCFCsandHFC) andarenumberedinthe500series,suchasR-500, R-501,andR-502.Unfortunately,mostofthesehave ahighozonedepletionratingsincetheyaremixtures containingCFCs.Forexample,R-502,animportant 1.ThisdocumentisCircular1165,FloridaCooperativeExtensionService,InstituteofFoodandAgriculturalSciences,UniversityofFlorida. Publicationdate:January1996.Reviewed:April1997. 2.C.DirelleBaird,professor;MichaelT.Talbot,associateprofessor,AgriculturalandBiologicalEngineeringDepartment,CooperativeExtension Service,InstituteofFoodandAgriculturalSciences,UniversityofFlorida,GainesvilleFL32611. TheInstituteofFoodandAgriculturalSciencesisanequalopportunity/affirmativeactionemployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,age,handicap,ornational origin.Forinformationonobtainingotherextensionpublications,contactyourcountyCooperativeExtensionServiceoffice. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/ChristineTaylorStephens,Dean

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IMPACTOFNEWREFRIGERANTREGULATIONSONPOSTHARVESTCOOLING Page2lowtemperaturerefrigerantisamixtureofR-22 (HCFC)andR-115(CFC)andwillsoonbeinshort supplyduetotheearlyphaseoutofCFCs.NONOZONEDEPLETINGREFRIGERANTSAnothercategoryofrefrigerantsarecalledHFCs (hydrofluorcarbons)whichcontainnochlorineand thushavenodamagingeffectontheozonelayer. IncludedinthisgroupisR-134aanewrefrigerant thatisbeingusedasareplacementforR-12. Otherrefrigerantsareclassifiedasinorganicand includeammonia,waterandnitrogen,whichdonot damagetheozonelayer. AlthoughneverusedextensivelyintheUSas refrigerants,hydrocarbonssuchasmethane,propane andbutanearegoodrefrigerantsexceptfortheir flammability;andtheydonotdepletetheozonelayer. Someworkisunderwaytomodifytheserefrigerants tomakethemnon/lessflammable. Ozonedepletionratingshavebeenassignedto eachrefrigerantandarebasedontheamountof chlorineintherefrigerantandhowfasttheybreak down.R-12isusedasthestandardsinceithasthe mostdetrimentaleffectontheozonelayerandother refrigerantsarecomparedtoit.Forexample,R-502 hasadepletionlevelratingwhichis30%thatof R-12,whileR-22hasanozonedepletionratingonly 5%thatofR-12.CFCshavethehighestdepletion levelratingswithHCFCsbeingmuchless,inthe orderof10%thatofCFCs,whiletheothercategories ofrefrigerants(HFCs,inorganicandhydrocarbons) haveazerorating.Ozone-depletingrefrigerantsare nowsubjecttoataxtieddirectlytotheirdepletion levelrating.GLOBALWARMINGAnotherenvironmentalconcernistheglobal warmingeffectofrefrigerantsdischargedintothe atmosphere.Ithasbeenestimatedthatduringthe 1980's,CFCsreleasedtotheatmospherewere responsiblefor24%ofthehuman-causedfuture globalwarmingeffect.Thiscontributionissecond onlytothe55%sharefromcarbondioxideemissions duringthisperiod.Table1showstheglobalwarming potentialofseveralrefrigerantscomparedtocarbon dioxide.Forexample,onepoundofR-12discharged totheatmospherewouldhavethesameeffecton globalwarmingas7100poundsofcarbondioxide overa20yeartimeperiod.However,someofthe HCFswhichwillreplaceCFCsarenotmuchbetter. Infact,itisestimatedthatsomeofthereplacement refrigerantswillactuallyincreasetheglobalwarming effectsincetheefficiencyofsomeofthesesystems willbeless,thusrequiringtheburningofmorefossil fuelandmoregenerationofcarbondioxide.The likelihoodoflessefficientsystemswillbemuch greaterduringthetransitionperiodinwhich"drop-in" replacementrefrigerantsareusedinexisting equipmentascomparedtocompletelynewsystems designedforthenewrefrigerants. Table1. Globalwarmingpotentialsoftracegases relativetoCO2 GlobalWarmingPotential IntegrationTimeHorizon TraceGas 20 years 100 years 500 years CarbonDioxide 1 1 1 Methane 6321 9 Nitrousoxide 270290 190 CFC-11 4500 3500 1500 CFC-12 71007300 4500 CFC-113 45004200 2100 CFC-114 60006900 5500 CFC-115 55006900 7400 HCFC-22 4100 1500 510 HCFC-123 31085 29 HCFC-124 1500430 150 HCFC-141b 1500440 150 HCFC-142b 37001600 540 HFC-125 4700 2500 860 HFC-134a 32001200 420 HFC-143a 45002900 1000 HFC-152a 510 140 47REVIEWOFIMPORTANTREFRIGERANTSTherearemanychoicesforrefrigerantsavailable-somearecurrentlyinuseoravailableandsomewill comeonlineinthefuture.Thefollowingisa discussionofsomeoftheimportantrefrigerantswhich

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IMPACTOFNEWREFRIGERANTREGULATIONSONPOSTHARVESTCOOLING Page3mayhelpyouinmakingmanagementdecisions concerningyourrefrigerationsystems. R-12 -amiraclechemicalwhenitwasfirst formulatedin1930s,itisnowviewedastheworst oftheozonebusters.Itsetsthestandardsfor ozonedepletionlevelwithascoreof1.Oneof thefamilyofCFCs,R-12canbeusedforlowto mediumtemperatureapplications.Itisvery stable,nontoxic,nonflammable,verycompatible withlubricatingoils,nonreactivewithmaterials usedinrefrigerationsystems,andhasfairlygood thermodynamicproperties.Manufacturingis scheduledtohaltattheendof1995.Afterthis, thesechemicalswillonlybeavailablein remanufacturedorrecycledforms.Several"dropin"replacementrefrigerantsarebecoming availableforR-12(R-134aisoneofthem).The conversioncanberelativelysimpleinthatvery littleequipmentmustbechangedandyoudonot havetobeextremelycarefulinchangingtheoil. Youmustgetmostofthemineralbasedoilout andreplaceitwithanewtypesyntheticoilmade forthespecificrefrigerantthatyouwillbeusing. R-22 -isaHCFCthathasonly5%oftheozone depletioneffectofR-12.HCFCsaremuchless stablethanCFCs;theybreakupatlowerlevelsof theatmospherewheretheydofarlessdamage. R-22ismostefficientformid-levelchillingand airconditioningsystems.Itcanbeusedforlower temperatureapplicationsbutsomeproblemswith lubricationmaydevelop.ProductionlevelsofR22willbefrozenin1996withcomplete eliminationby2030.Itisrelativelyeasytoswitch fromR-22toammoniaifyouhaveacompressor engineeredforboth(requiredpipesizeand compressorloadsaresimilar)butyoumustswitch copperandbronzefittingstosteel. R-502 -thisisamixtureofR-22andR-115 designedtomakeR-22workbetteratlow temperatureapplications.Itisgettinghardto findasproductionofR-115windsdown,itison thesamephaseoutscheduleasR-12.R-502has anozonedepletionlevelone-thirdthatofR-12. ItiseasytoconvertfromR-502toR-22since normallyonlytheexpansionvalvesneedtobe changed.However,R-22willnotperformaswell atlowtemperatureapplicationasR-502. Ammonia(R-117) -isusedinlargerefrigeration plantsandismuchcheaperthanCFCsand HCFCs.Apparently,ammoniadoesnotdamage theozone;however,itisflammableandtoxicto humans.Theproblemwithtoxicityislessened sinceitisselfalarminginthatitsmellssobad thatyouknowitiscoming.Ammoniaalsohas thedisadvantageofattackingcopperandbrassas wellasrequiringspecialarrangementforoil circulation.However,ammoniahasthebest thermodynamicpropertiesofanycommon refrigerant.Duetoitstoxicityandflammability, itcannotbeusedinadirectsystem,butmustuse anintermediateheattransferfluid,usuallywater. Thismeansthattheevaporator(coldcoil)can notbelocateddirectlyintheairstreamorcome incontactwithfoodproducts.Anindirectsystem isnotusuallyadisadvantageforcoolingproduce andmaybeusedasanadvantage.For hydrocoolingsystemsitisnotanissuesincethey areindirectbydesign.Foraircooling,indirect systemsareslightlylessefficientsincetwoheat exchangeprocessesmustoccur.However,they havetheadvantageofthermalstorage(wateror ice)whichcouldmaketheoverallcoolingprocess moreefficientandmorecapableofhandling varyingcoolingloads.Also,water-to-airheat exchangersresultinhigherhumidityair. Ammoniasystemsmayhaveahigherinitialcost, partlyduetotheaddedcostofindirectsystems, butusuallyhavealongerlifeandlowertotalcosts overthelifeofthesystem.Also,ammoniahasan ozonedepletionratingofzero. SubstituteRefrigerants(LowOzoneDepleting) todistinguishthenew"drop-in"refrigerantsfrom theoldFreons(aDuPontbrandname).DuPont isusinganewtradenameSuva.Thedepletion levelpotentialofthesechemicalsisverylow,at orslightlylessthanthelevelofR-22.SuvaMP39and66areformulatedtoreplaceR-12and SuvaHP-80and81toreplaceR-502.These substituterefrigerantsarereportedtoperform withnoreductionincapacityorefficiency.In contrast,newequipmentspecificallydesignedfor usewithR-134acanbemoreefficientthanitsR12counterpart.AslightlydifferentcompoundR69manufacturedbyRhone-Poulenc,isalso designedtoreplaceR-502. SubstituteRefrigerants(NonOzoneDepleting) R-134aisahydrofluoracarbon(HFC)withan ozonedepletionratingofzerowhichhasbeen developedtoreplaceR-12andisnowbeingused inautomobileairconditioners.Adirectswitchto R-134ainasystemdesignedforR-12isreported toresultina10-15%decreaseinrefrigeration

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IMPACTOFNEWREFRIGERANTREGULATIONSONPOSTHARVESTCOOLING Page4capacity.ThereareotherHFCssuchasR-125 engineeredtoreplaceR-122andR-143adesigned toreplaceR-502.SuvaHP-62isalsoa replacementforR-502.Sinceallofthese refrigerantsareHFCs,theyhaveanozone depletionratingofzero.SEALLEAKSANDCONSERVE REFRIGERANTRegardlessofthetypeofrefrigerantused,a concertedefforttoeliminateleaksshouldbemade. Thiswillreduceyouroperatingcostsaswellasavoid potentiallegalaction.SinceJuly1,1992ithasbeen illegaltodischargeozonedepletingrefrigerantsinto theair.InitiallytheEnvironmentalProtection Agency(EPA)wasmostconcernedwithintentional ventingusuallydonebyrepairmenwhowouldempty asystempriortoservicingit.Nowunderthe authorityofthecleanairacttheyarelookingfor leakysystems.Leaksmaybemonitoredthrough purchasesofrefrigerants.Contractorssuspectthat theymaysoonberequiredtoaccountfortheuseof therefrigerants.Futureregulationsmayrequirethat yougiveareasonforpurchasingrefrigerants,suchas enlargingasystem.Stifffinesareassociatedwiththe EPAregulations.Forexample,afineupto$25,000 canbeassessedforunlawfulreleaseofaCFCanda $10,000rewardcanbemadeforreportingaviolation. Thefinancialincentivetoplugleaksislikelyto increase.Historicallyitwascheapertojust periodicallyrefillaleakingsystembutthathas changed.Ozonedepletingrefrigerantsarenow subjecttoataxtieddirectlytotheirdepletionlevel rating.Forinstance,everytimethetaxonR-12 increasesby$1thetaxonR-502jumps30cents.The taxonR-12jumpedto$5.35perpoundin1995and willincrease$0.45peryearuntilyear2000.This rapidincreaseinpricecausesconcernaboutillegal importsofCFCs.Refrigerationindustryofficialshave recentlyreportednumerousofferstopurchaseCFCs atpriceswellbeloweventheamountoffederalexcise tax.Miamicustomsagentsreportthatillegal refrigerantsaresecondonlytodrugs.Thenew"dropin"refrigerantsdesignedtoreplaceCFCsare expensive,butarebecomingcheaperthantheCFCs asthetaxincreases.A25-tonsystemmightcontain between100and300poundsofrefrigerant,making thecostofrefrigerantamajoritem. Asrefrigerantsgetmoreexpensive,theincentive tocleanandreusethemwillincrease.Thereare manyrefrigerantrecoverysystemsbeingmarketed today.Anownercanrecoverandreuserefrigerantas longasitisusedinasystemhe/sheowns;refrigerant cannotbesoldortransferredtoanotherowner, undercurrentregulations.MANAGINGYOURREFRIGERATION SYSTEMSItisexpectedthatmanyownersofrefrigeration systemswillfaceimmediaterefrigerantshortagesin 1996whichmayleadtohigherpricesanddifficulty obtainingCFCs,orderingdelaysforretrofitpartsand newequipment,andtemporaryortotalshutdowns. Somemanufacturershavealreadyreportedatripling oftheirdeliverycycles,uptosixmonths.Nodoubt allofthisisconfusingandfrustratingtoyouasan ownerormanagerofrefrigerationsystems.Crisiscan beavoidedbyproperplanningandimmediateaction. Rule608(NationalEmissionsReduction Program)oftheTitleVICleanAirActof1990 requiresminimalrecordkeepingwhenCFCand HCFCrefrigerantsarepresent.Youshouldhavethe followingfilesinyourrecords: Recordsofrefrigerantpurchases. Acopyofyourrecoveryequipmentcertification form. Recordsofemployeetraining. Recordsofrecoveredrefrigerant. Facilityequipmentservicedandservices performed. Recordsofleakdetection. Recordsofrefrigerantdisposition. Anenvironmentalpolicystatement. Thewrittenpolicyshouldstatethatyourcompany andallitsemployeeswillobeyalllawsapplicableto thisindustryandthatanyemployeewhoknowingly ventsCFCorHCFCwillbeterminated. Suspicionsaregrowingonthepartofregulators duetothefactthatlittlerefrigerantiscominginfor reclamationandthatonlyasmallportionofthe certifiedrecoveryequipmenthasbeenpurchased. Somefineshavebeenlevied,butnotnearlywhat couldbe."Norecords"isnotanexcuse. TheEPAsuggeststhefollowingmeasuresasa meansofgettingstartedwithapracticalapproachto managingrefrigerants. 1.DesignateaCFC/HCFCmanager. 2.Inventory,trackandmanageexistingrefrigerant stocks.

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IMPACTOFNEWREFRIGERANTREGULATIONSONPOSTHARVESTCOOLING Page53.Quicklydevelopandimplementanactionplan. Underthisactionplanyoucouldrecycleand conserverefrigerants,reduceleaks,retrofit equipmentwithsubstitutesandreplaceequipment wheneconomicallyfeasible. Supposethatyoudeterminethatagivensystem hasroughlytenyearsofusefulliferemaining.Should youretrofitthesystemwithanewsubstitute refrigerantorshouldyoureplacethesystemwitha completelynewrefrigerationsystem.Itissuggested thatyouneedtoknowthefollowingitemstomake thisdecision. Knowcurrentevents,includingozonedepletion, climatechange,internationalactivitiesandclean airact. BecomefamiliarwithexistingEPAregulations, includingphaseoutandtaxonCFCs/HCFCs, prohibitionofventingandleakage,andrecycling rule. Becomefamiliarwiththesubstituterefrigerants andnewequipmentusingnewrefrigerants. Knowyourownequipment,includinghoursof usage,maintenanceandrepairhistory,schedule forrecommendedoverhaul,ventilationratesin equipmentroom,refrigerantavailabilityandcost, andtotalnumberofrefrigerationsystemsunder yourmanagement. Knowtheenergyimplications,includingenergy cost,currentandfuturetaxes,efficiencyofyour equipment,efficiencyofnewequipment,your coolingloadrequirements,andenergyefficiency rebatesorotherincentivesfromutilities companies. Knowtheenvironmentalandsafetyimplications ofrefrigerantoptions. Knowyourbuildingorplantmodernization schedule.SUMMARYAmanagermusthaveagoodunderstandingof refrigerantsandrefrigerationsystemsinorderto makewisedecisionsforthefuture.Because regulationsandtherefrigerantsthemselvesarestillin suchastateofflux,thereisnogoodmapforplanning ahead.Thisisparticularlytrueifyouareadding refrigerationnow.Convertingfromonerefrigerantto anothermayrequirereplacementofexpensive componentsandlubricants.Also,arefrigeration systemusuallylosesefficiencyand/orusefullifewhen asubstituterefrigerant(oneforwhichthesystemwas notdesigned)isused.Manyofthenewrefrigerants arelessstable,morecorrosiveandlesscompatible withlubricantsthanweretheconventional refrigerants.Therefore,onecanexpectthatnew refrigerantsandnewsystemswillexperiencemore breakdownsandrequiremoremaintenancethanthe conventionalsystemswhichweredevelopedovera longperiodoftime.Itnormallytakes5-10yearsto design,developandtestnewrefrigerationequipment. Ifafterconsultingwithyourrefrigerationexperts, youareuncertainofwhichdirectiontotake,you mightconsideracompromisesuchaspurchasingaR22systembutusingsteelinsteadofcoppersothatthe refrigerantcouldbeconvertedtoammoniainthe futureataverylowcost.Somecodeswillnot currentlyallowtheuseofammoniabutmaychange astheCFCsandHCFCsarephasedout.Youmay alsowanttokeepintouchwithEPAregulations throughtheirEPAOzoneHotline(800-296-1996).