Refrigerant Charge after Conversion

[edorsbon]

In order to comply with the environmental people, I need to know the amount of refrigerant that is used to charge several centrifugal chillers. The chillers are from the 60’s or 70’s. I can find the amount of refrigerant originally used to charge the chillers, but they have all been converted to a non-CFC type refrigerant. My question is, if a unit needed 1000 lbs. of R-12 will it need 1000 lbs. of HFC -134a. If the conversion is not done on a mass basis, is it done on a volumetric basis or on the basis of cooling capacity? I have the same question for R-114 to HFC-123. If anyone can help it would be appreciated.

 

[imok2]

R-12
8. Charge with Suva® refrigerant. In general, the
refrigeration system will require less weight of
the Suva® 134a than of R-12. The optimum
charge will vary depending on the system design
and operating conditions. For most systems the
best charge size will be 75–90% by weight of
the original R-12 charge.
For best results:
• It is recommended that the system be initially
charged with about 75% by weight of the
original charge.
• Add the initial charge of Suva® refrigerant
to the high-pressure side of the system
(compressor not running) until the system
and cylinder pressures equalize. Then connect
to the low-pressure side of the system, start
the compressor, and load the remainder of the
refrigerant slowly to the suction side of the
system.
For entire article go to

http://www.dupont.com/suva/na/usa/literature/pdf/

For R-11 or R114 with go here:

http://www.dupont.com/suva/na/usa/literature/pdf/h42443_4.pdf

 

[edorsbon]

Thanks for your help imok2