R134a Retrofit For R12 Refrigerant Gas

Harp® 134a is a zero ozone depletion (ODP) hydrofluorocarbon (HFC) refrigerant. It is used on its own as a pure refrigerant and as a component in a large number of refrigerant blends. It is widely used in new equipment that would have previously used CFC R12 and can with specific modifications be retrofitted into exiting R12 equipment. APPLICATIONHarp® 134a applications include automotive air conditioning, chillers, medium temperature commercial refrigeration, domestic refrigeration appliances and transport refrigeration. PROPERTIES AND PERFORMANCEHarp® 134a is designed to meet the needs of many air conditioning and medium temperature refrigeration systems. Harp® 134a is a single component refrigerant, rated A1 by ASHRAE (lowest levels of toxicity and flammability), has zero ozone depletion potential and a Global Warming Potential of 1430. LUBRICATIONEither Polyolester (POE) or Polyalkylene glycol (PAG) for auto Air conditioning lubricants must be used with HARP® 134a. It is not miscible with mineral oil or alkylbenzene lubricants found in many systems. When retrofitting, a lubricant flush procedure is necessary to reduce the original oil content below 5% of the total oil charge. New R134a equipment will be charged with the OEM recommended lubricant, ready to use with Harp® 134a. CHARGINGCharging with Harp® 134a can be done either as a vapour or a liquid. End-users should check with the equipment manufacturers guidelines for specific charging instructions. RETROFITTINGWhen retrofitting R12 systems to Harp® 134a, it is necessary to replace the existing lubricant with POE oil, except in some automotive retrofit applications, which require PAG oil. In most cases, the mineral oil or alkylbenzene oil levels must be reduced below 5% of the new POE charge. Check with OEMs for any specific recommendations regarding viscosity grades or procedures. Remove as much of the existing lubricant as possible, add POE, and run the system on R12 for some time. When the residual oil concentration is appropriate, remove R12, replace the filter-drier, and charge Harp® 134a. MATERIAL COMPATIBILITYWhenever retrofitting air conditioning or refrigeration systems, compatibility of system materials must always be taken into consideration. Items such as elastomers, hoses, and filter-driers respond differently to different refrigerants and oils. For these reasons, before performing any refrigerant retrofit, Harp International recommends contacting the OEM for specific recommendations.