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Chiller Rerating

Modifying a refrigeration chiller to use a non-CFC refrigerant

Environmental regulations are prompting many companies to switch to non-CFC refrigerants. Simply substituting a new refrigerant in an existing unit will typically result in a 5% to 30% loss in cooling capacity and up to a 20% increase in power consumption. For most installations, modifying a chiller to use alternative refrigerants is far less expensive than replacing the machine. Concepts NREC offers cost-effective chiller conversions from CFCs to new refrigerants using high-efficiency replacement impellers that maintain cooling capacity with little or no increase in power consumption.

High-performance replacement impellers and kits

Using proprietary, state-of-the-art analysis and design technology to substantially improve compressor performance, Concepts NREC has complete CFC replacement solutions currently available for the following refrigeration chillers:
 

Refrigeration chillers CFC replacement kits

Carrier 17M38/5
Carrier 17M63
Carrier 17M64
Carrier 17SA40
Carrier 17SA32
Carrier 18T471X
Carrier 17DA
Carrier 19DK
Carrier 19DH
CQGM
Rosenblatt 1881
Snyder General CEH087K
Turbomaster M-Series
Worthington 62EH
Worthington 51EH
York M238
York M255
York M355

Complete conversion services

Concepts NREC can supply precision, high-performance replacement impellers machined from forged blanks (to ensure material strength), as well as complete conversion kits with refurbished older components and new compatible parts (nozzle rings, diffusers, shafts, locknuts, seals, gaskets, lubricants, etc.). Concepts NREC can also manage the entire conversion project including reassembly and acceptance testing of the newly converted machine while working with onsite maintenance staff, chiller service providers, or nationally recognized product support organizations.
 

Options for Converting Refrigeration Chillers to Non-CFC Refrigerants

Chiller owners using CFC refrigerants have several options available for conversion. Only impeller replacement can provide the full capacity of the original chiller with minimal impact on operating costs, while economically using existing equipment. A machine can be returned to its original capacity with a minimum of downtime by retaining all major components except the impellers. Conversion options include the following alternatives:
State-of-the-art centrifugal compressor design and manufacturing technologies help produce impellers with higher operating efficiencies. High-efficiency impellers are optimized for the new refrigerants to allow chillers to maintain capacity without a serious impact on power consumption.

State-of-the-art centrifugal compressor design and manufacturing technologies help produce impellers with higher operating efficiencies. High-efficiency impellers are optimized for the new refrigerants to allow chillers to maintain capacity without a serious impact on power consumption.



The new refrigerants change system operating conditions that require the compressor to provide different pressure ratios and flow rate.

The new refrigerants change system operating conditions that require the compressor to provide different pressure ratios and flow rate.



A compressor with new impellers allows chiller owners to avoid the added operating cost of increased power consumption resulting from some methods of regaining original chiller capacity.

A compressor with new impellers allows chiller owners to avoid the added operating cost of increased power consumption resulting from some methods of regaining original chiller capacity.



Concepts NREC impellers economically restore cooling capacity through advanced aerodynamics and high-quality machining.

Concepts NREC impellers economically restore cooling capacity through advanced aerodynamics and high-quality machining.



Refrigerant substitution effectively moves the system design point relative to the compressor's performance map.

Refrigerant substitution effectively moves the system design point relative to the compressor's performance map.
  • Stockpile CFCs and prevent leakage
    Users can continue operating with CFCs knowing that refrigerant purchases will become increasingly expensive and difficult to acquire. There are also severe federal penalties for releasing CFCs into the atmosphere, so leakage prevention is critical.
  • Use a substitute refrigerant
    CFC refrigerants can be replaced with HCFCs or HFCs. However, the new refrigerants can react destructively with the elastomers and lubricants commonly used in present equipment. Substitution must also include the replacement of original gaskets, seals, and other vulnerable components using ones compatible with HCFCs or HFCs. Direct substitution also generally results in substantial performance penalties.
  • Increase compressor operating speed
    Increasing operating speed will often regain original chiller capacity. Electric drives almost always require physical modifications to increase speed, including bearing and gearing changes, motor rewinding, or motor replacement. Steam turbine drives may require refurbishment or even replacement to handle the speed and power levels required. Because overall power consumption goes up significantly, increased energy costs should be considered when evaluating this alternative.
  • Replace chiller equipment
    Original performance can be returned by completely replacing all or part of the chiller system with new equipment designed to operate with new refrigerants. Equipment manufacturers argue that older chillers are inefficient and should be replaced simply due to age. However, chiller compressors operate in a relatively benign environment and an extended life cycle can be expected of older machines that are well maintained. The parts that do ordinarily wear must be replaced in any case as part of a CFC conversion. To accommodate new equipment, extensive and costly facility modifications are often required. It can be far less expensive to bring an older unit up to current specifications than to completely replace it.
  • Use Concepts NREC replacement impellers
    Replacing the original compressor impellers with a more efficient, modern design returns original performance. Most of the original components and operating conditions, including drive speed, are retained. The impellers are removed and new, high-performance impellers are reverse engineered or designed, precision manufactured, and assembled onto the original shafts.

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