View Full Version : Old R22 Carrier Chiller rebuild to Freecooler

13-07-2010, 07:40 PM

In our plant, we have 2 Carrier 30G/H series chillers on the old R22 refrigerant charge, that we took out of production this year. Mainly because of the R22 problematics and stocking of this charge.

Because we are looking for the possibility to add freecoolers to our existent ice water circuit (setpoint 11C), i was wondering if it was possible to use the old Carrier Chillers for freecooling purposes ?

I would remove the compressors, heat exchanger, etc, and would connect the icewater to the condensor pipes. (with a circulation pump offcourse) In an ambient temperature that is low enough, i would turn on the ventilators of the condensor, so that the cold air flows through the condensor, and cools the icewater.

In order to prevent the system from freezing, i thought of adding a valve to bypass the system so that the water keeps flowing through the condensor, and passes a small electrical heating resistor. In that way, i would monitor the circulating water and keep it warm enough.

Is this a good idea ? I know that the rentability will not be as good as a new specific freecooler, but i hate it that the chillers are just standing there...

Thanks for the replies !

13-07-2010, 10:39 PM
I don't see any major problems with that however.....

The condenser coil will need flushing/cleaning inside to remove any residue of the lubricating oil that was in the system.

You may need to modify the coil headers to allow better water flow compared with flowing refrigerant.

14-07-2010, 05:56 PM
Like Brian say's it is possible but i wouldn't think it would be very economical as the old 30GH coils are not the most effecient out there

14-07-2010, 07:36 PM
Hi, I would also consider the flow rate and pressure drop.
There is a large "Hot Gas" Header with many inlet tubes from your existing discharge pipes, and only a small header "Subcooled Liquid" on the outlet to the drier cores!
There could be some extensive Brazing required. Good luck- and dont forget the "HOT WORKS" permit.

20-07-2010, 06:51 PM

thanks for the replies. i made another adjustment to get the system free of freezing: Connecting the icewater to the existing heat exchanger, and make a separate watercircuit containing glycol.

These works need to be done;

1) disconnecting compressors and expansion valves.
2) Make a new circuit from the heat exchanger to the condensor tubes.
3) Make the condensor collectors as big as possible to avoid a pressure drop.
4) connect a circulation pump between the heat exchanger and the condensor tubes.
5) Connect the ventilators to frequency drives, or with contactors (like originally).

You guys see this working ? Or am i being to optimistic ??

24-09-2010, 06:09 PM
Condenser & water coils are circuited completely differently! What are you doing? Just buy a new adiabatic cooler!