We have been asked to perform a Refrigerant Conversion from R-22 to Isceon
59 (R-417a). This drop in refrigerant. Shortly after the conversion, Isceon
recommended that Isceon 59 no longer be used in Liquid DX Chillers and that
such chillers should only use their new product, Isceon 29 (R-422D)
Inquiries to the factory gave us no definitive answer as to why the Isceon
59 was no longer compatible with Liquid Chillers. We have used Isceon 59 on
several packaged R-22 units with great success. We noticed in the chiller
that it was more difficult to maintain a stable Superheat at the compressor
and we experienced some floodback wiping out a compressor. The subject
chiller is a 2 circuit, 60 ton unit, with 4 scroll compressors.
The owner finally obtained the Isceon 29 and we are ready to proceed with
converting from Isceon 59 to Isceon 29. The DuPont literature gives little
indication as to what we can expect with the conversion including superheat
In short the question is...
Does anyone have experience with this? It is a remote site and we only get
one chance at it because there is no availability of parts for weeks. Is
there any indication as to changing the element on the R-22 TXV to another
type of element. I notice that the PT charts for Isceon 29 are more in line
with the PT charts for R-22 than the Isceon 59 replacement.
Any tips on this one from you experts...