Technical Information DuPont Suva - Altair …

1 Technical InformationDuPont suva refrigerantsRetrofit Guidelines for DuPont suva 407 CIntroductionOver the past five decades, HCFC-22 (R-22) hasbeen used as a refrigerant in various refrigeration,industrial cooling, air conditioning, and heatingapplications. The low ozone depleting potential ofR-22 compared to CFC-11 and CFC-12, along withits excellent refrigerant properties have helpedfacilitate the transition from CFCs. However,HCFCs, including R-22, are scheduled for eventualphaseout under the Montreal Protocol. DuPontsupports the current Montreal Protocol phaseoutschedule for HCFCs and is committed to helping theindustry prepare for the eventual phaseout of has developed DuPont suva 407C asthe similar pressure replacement for R-22 in positivedisplacement, direct expansion air conditioners andheat pumps.

2 This refrigerant is also suitable for usein many medium temperature refrigeration systemsthat formerly used R-22. suva 407C is the regis-tered trademark for a blend of HFC-32/HFC-125/HFC- 134a with a corresponding composition of 23/25/52 suva 407C is commercially availablefor retrofit of existing equipment and as a long-termreplacement option for R-22 in new these retrofit guidelines, many R-22 systemscan be retrofitted for use with suva 407C in airconditioning, heat pump applications and refrigera-tion applications, to allow existing equipment tocontinue to operate safely and efficiently, even afterR-22 is no longer Propertiesand SafetySuva 407C offers improved environmental proper-ties versus R-22, with an equivalent Global Warm-ing Potential (GWP) and zero Ozone DepletionPotential (ODP).

3 Refer to DuPont Technical Bulle-tin P-407C/410A for more detailed Information onproperties and performance characteristics forSuva 407C. Refer to the Material Safety DataSheet (MSDS) for safety Information on the useof this Compatibility andThermodynamic PropertyInformationThe compatibility of plastics and elastomers shouldbe considered before retrofitting to suva 407C/polyol ester oil. Testing shows that there will be noone family of elastomers or plastics that will workwith all the alternative refrigerants. It is recom-mended that gaskets, shaft seals, and O-rings bereviewed with the equipment manufacturer experience has shown that some systemsretrofitted directly from CFC or HCFC to HFCrefrigerants can have increased leakage of elas-tomers (o-rings, gaskets) following removal of theCFC or HCFC refrigerant even if the existingelastomer is compatible with the HFC is because the old elastomers will have swelleda certain amount due to exposure to the CFC orHCFC refrigerant and will swell a different amountwhen exposed to the HFC.

4 The difference inswelling may cause a poor seal. If this problemis encountered, replace the used O -rings withnew ones of the same material. They will thenswell due to exposure only to the new refrigerantand will seal as compatibility Information is availablethrough the DuPont suva Answer Line,1-800-235-7882 or at the DuPont suva Website, under hypertext link Tech Info . On the website, general property andmaterial compatibility Information for suva 407 Cis contained in the Properties, Uses, Storage andHandling (PUSH) section. Thermodynamic propertyinformation is available in the Tech Info areaof the website, in the Thermodynamic DuPont Oval Logo, DuPont , The miracles of science ,and suva are trademarks or registered trademarks du Pont de Nemours and 1 DuPont suva 407C and R-22 Physical PropertiesPropertySuva 407CR-22 Boiling Pt.

5 (1 atm) F ( C) ( ) ( )Vapor Pressure, SatLiquid at 77 F (25 C)Psia (kPa) (1174) (1043)Liquid Density at 77 F (25 C)lb/ft3 (kg/m3) (1134) (1195)Density, Sat. VaporAt 77 FC (25 C)lb/ft3 (kg/m3) ( ) ( )Ozone Depletion Potentialas compared to R-11(R-11 = 1) Warming PotentialCO2 = 100 Year ITH*16001700**Integrated Time HorizonLubricantsLubricant selection is based on several factors,which can include lubricant return to the compres-sor, lubricity, and materials compatibility. Polyolester lubricants are recommended for use in mostHFC systems. There are many polyol ester lubri-cant manufacturers; to determine which lubricant isrecommended for the refrigeration system, contactthe compressor manufacturer, equipment manufac-turer, or a DuPont care should be taken when handling polyolester lubricants due to their tendency to absorbwater.

6 Contact with air should be minimized, andthe lubricant should be stored in a sealed retrofitting R-22/mineral oil systems to suva 407C/polyol ester lubricant, to achieve equivalentmiscibility the residual mineral oil should be around5 wt. % or less of the total lubricant used in thesystem. Allowable residual mineral oil is highlydependent on system configuration and operatingconditions. If the system shows signs of poor heattransfer in the evaporator or poor oil return to thecompressor, it may be necessary to further reducethe residual mineral oil. A series of successivelubricant changes using polyol esters can normallyreduce the mineral oil concentration to low manufacturers have developed field testmethods for determining the weight percent ofmineral oil in polyol ester lubricant.

7 Contact thelubricant manufacturer for the recommended Characteristicsin Existing R-22 DesignsSuva 407C provides similar energy efficiency andcapacity to R-22 with a lower discharge temperatureand slightly higher discharge pressure. As a result,minimal system modifications are anticipated whenretrofitting R-22 systems to suva 407C. Originalequipment manufacturers should be contacted todetermine if discharge pressure controls will need tobe adjusted to compensate for the higher dischargepressure. Table 2 summarizes the actual perfor-mance of suva 407C versus R-22 for both coolingand heating modes in different units designed forR-22. The units were not modified or optimized forperformance with suva 2 Performance of DuPont suva 407C Relative toR-22 in Multiple Air Conditioners and Heat PumpsSuva 407 CRange of Performance: Cooling Mode*Relative Capacity, %98 to 106 Relative Energy Efficiency Ratio (EER), %93 to 97 Change in Discharge Temperature, 15 to 8 F ( C)( to )Change in Discharge Pressure,+15 to +40psi (kPa)(+103 to +276)Range of Performance: Heating Mode**Relative Capacity, %93 to 106 Relative Energy Efficiency Ratio (EER), %94 to 97 Change in Discharge Temperature, 18 to 0 F ( C)( 10 to 0)Change in Discharge Pressure,+9 to +34psi (kPa)(+62 to +234)Values compared to R-22 in unmodified split system heat pumpsand an unmodified window air conditioner using the.

8 **DOE cooling test conditions A and B and**DOE heating test conditions E and of Leak/Rechargeon PerformanceSuva 407C has excellent refrigerant behavior, evenin the event of vapor leaks from a two-phase regionof a refrigeration system and subsequent there is a suva 407C leak from an operatingunit in a two-phase region where mixing occurs(heat exchangers or expansion device), both thevapor and liquid will leak from the unit. The compo-sition of the refrigerant left in the system will remainessentially unchanged from the original recharging suva 407C to the system to getback to the original charge size, the performance ofthe unit will be the same as its original performancewith suva 3 Theoretical Unit Performance After 50 wt% Vapor Leaks and Recharges of DuPont suva 407 CCompressor DischargeRecharge COP,* %Rel.

9 Cap.,** %Temperature, F ( C)Pressure, psig (kPa)0100100178 ( )261 (1903)110195177 ( )246 (1800)210193177 ( )239 (1751)310192177 ( )236 (1731)410191177 ( )235 (1724)510191177 ( )235 (1724)**Coefficient of Performance (measure of energy efficiency) relative to the Coefficient of Performance of the original charge of suva 407C.** refrigerant cooling capacity relative to the capacity of the original charge of suva , if the unit is not operating and there isa vapor leak from a static two-phase region, thecomposition of the refrigerant that remains in theunit will change. The remaining refrigerant will bemore concentrated in the high boiling component(HFC- 134a and less concentrated in the lowerboiling components (HFC-32 and HFC-125). Theeffect of this composition shift on the performanceof suva 407C is summarized in Table 3.)

10 Thesedata reflect the theoretical performance of suva 407C for multiple recharges of a system after50 wt% of the refrigerant charge is lost througha vapor leak above a two-phase important observations from the data gener-ated in this leak/recharge study are:During a vapor leak, the HFC-32 (the flammablemixture component) remaining in the system de-creases in concentration, such that the mixtureremains efficiency is maintained and dischargetemperature and discharge pressure decrease duringthe vapor leak/recharge loss is limited to 9% as the performanceof suva 407C levels out after four 50% leak/recharges. Note further that the theoretical studyreflects a worst case scenario. In practice, lesserchanges are normally experienced, as illustratedby results from a heat pump leak experimentwhich showed the capacity loss was maintainedat 4% after the second 407C is suitable as a replacement for R-22 inmedium temperature (20 F to 40 F) evaporatorconditions but loses capacity at lower temperatures,where higher pressure refrigerants such as suva HP62 are recommended.