Re: More R-417A Questions
Hi Glabah
R417a shouldn't need any major changes to the system as it will work with mineral or POE oil.
Its characteristics are quite similar to R22 so the exsisting tevs should just require a minor tweak.If I recall correctly charge weight required to replace R22 is the same charge.
Condenser and evaporator coils should be ok without modification.
Having said all that the only way to be certain that it will suit your requirements is to try it.
BritCit_Juve
Re: More R-417A Questions
Thanks. The more I've read the more it sounds like our best option, vs. having to deal with POE oils or redesign around R-410or other high pressure system.
Re: More R-417A Questions
I have experience of retrofitting R59. i tried it on a number of chillers from 11kW to 75 kW input power. Things to look out for, slightly reduced amount of refrigerant for charging. Reduced capacity of chiller unit by about 10%. Increase in efficiency slightly. You may need to change superheat settings.
All in all I bearing in mind that I started this about 4 / 5years ago, I have chillers still running on the original charge and still performing well!.
Also look out for R29 which has been designed slightly differently for water chillers.
NB. I only tried the retrofit on recipricating units, not screws?
Re: More R-417A Questions
liebert hiross have been using R417a now for a while as a replacement for R22 in their older range of close control units i hear it works well for these type applications but no so good for low temp systems
Re: More R-417A Questions
About Five years ago I was involved in retrofitting some Hitachi screw chillers from R22 to R59. When we ran the chillers the R59 gave us a very low discharge superheat. As the Hitachi screw requires a higher discharge superheat (30) we put the chiller back to R22. The same thing happened when we retrofitted an old Hitachi VRF system. R59 seems to work okay on small splits, but not screw chillers and VRF