Chiller retrofit

[HARRY 7]

Hello to everybody.Can anybody suggest which refrigerant to use,to retrofit chiller TRANE RTAA?

[hookster]

I would look at R407c as an option or R427A but you need to consider your chiller application, age and all the other yadda yadda yadda!

[HARRY 7]

Hi Hookster.Thanks for reply.I believe tha chiller is about 20 years.It chills water for aircondition applications.Have you ever done this retrofit to this machine with the refrigerants you mentioned?Did you have problems during the operation of the chiller?

[hookster]

I have done a similar project with a chiller of similar capacity and we chose R407c for the retrofit to ensure it was a low GWP refrigerant and oil compatibility problems were reduced. The screw compressor operates very well on 407c without worry about liquid slugging worries etc.
We opted to replace the expansion valves to electronic and used the Carel Ex valve with their EVD driver (very simple to set up) to compensate for any problems with glide.

I have to note for anyone considering retrofitting that this chiller was in very good condition and had been well maintained. The chiller is still operating today and it was the sweetest retrofit I have done with the client over the moon

If you are going to consider a retrofit and there has been reduction in condenser surface due to coil fail or leakage I would advise that this unit is due for replacement rather than retrofit.

[HARRY 7]

This chiller has already an electronic expansion valve.So it cannot change.The chiller has screw compressors.Was your retrofit in chiller with screw compressors?Did you have issues with false alarms,because of the little change in pressure-temperature of the refrigerant?