Operation and Maintenance Planning for the CFC Phaseout
Because of the phaseout of the manufacture of CFCs by 1996, the owners of most air conditioning and refrigeration equipment (AC&R) must determine now the manner in which they want to respond to this situation. There are several possibilities; continue to use the existing refrigerant, convert the refrigerant to analternate, or replace the equipment. It must be remembered that only the manufacture of the refrigerants will be prohibited, not the use of them. A decision to continue using the existing refrigerant will result in increasing costs due to a decreasing supply of that refrigerant. At some time in the future, the owner will be faced with either of the other options. At the least, the owner should attempt tocontain the refrigerant by updating purge units on low pressure centrifugal chillers, and eliminating leaks on all systems. A decision to convert the equipment to a new refrigerant will require detailed engineering and economic analyses of the existing system. An engineering analysis to determine the current and predicted performance should be made. Changes to components may be necessary to utilizethe new refrigerant or to return performance to acceptable values. A decision to replace the equipment can be made for a number of reasons. When the equipment is near the end of its useful life, conversion is not cost effective. When capacity is already marginal, either new properly sized equipment or additional equipment will be necessary to provide the capacity required. The owner should decidenow what steps will be taken for each system. The strategy should cover the possibility of an equipment failure occurring before the plan is implemented. The owner may decide at that time to convert or replace the equipment as the plan determines. The following pages describe some of the recommendations involved in the conversion of systems to alternate refrigerants.
Our advice is intended to complement the equipment manufacturers’ recommendations - not replace them. If you have doubts about any particular procedure, contact your equipment service representative. STRATEGIC CHOICES FOR EXISTING CHILLERS CONTAINMENT L P Chillers Containment - maintain the original type of refrigerant in the chiller by utilizing service productsand techniques as listed below: Low pressure chillers - CFC-11, CFC-113 1. 2. 3. 4. 5. H P Chillers Install high efficiency purge unit Install pressure sealing system to keep unit slightly pressurized to prevent air infiltration when unit is shutdown Install a relief valve assembly in place of the rupture disc Install service valves to isolate components that need to be serviced during regularmaintenance schedules Use good service practices such as frequent leak testing and using refrigerant recovery devices when removing the refrigerant.
High pressure chillers - CFC-12, R-500, HCFC-22 1. 2. Install service valves to isolate components that need to be serviced during regular maintenance schedules Use good service practices such as frequent leak testing and using refrigerant recoverydevices when removing the refrigerant.
#448 (rev 06/08)
©2008 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved.
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CONVERSION of CFC-11 or –113
Conversion - converting to a non-CFC refrigerant Converting a CFC-11 or CFC-113 chiller to HCFC-123 1. 2. 3. 4. 5. 6. 7. 8. 9.Perform an engineering analysis to determine chiller performance after conversion Replace all original gaskets and O-rings that are not compatible with HCFC-123 Replace or rewind a hermetic motor whose materials are not compatible with HCFC-123 Replace impeller with one designed specifically for HCFC-123 to regain lost capacity Flush system of mineral oil as per manufacturer’s recommended procedures...
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