Paul,

Could you elaborate a little more, your information is a bit vague to make a proper reply.

To give you some idea, the general problems with R22 replacment is which long term alternative refrigerant to use, R407C is the interim blend refrigerant, recognised as the retrofit drop in for R22 but as you touched on has flaws with regard to compressor failure, failures which not only effect refrigerant replacment but R407C systems in general. The problems with R407C are numerous (differences in oil, mineral/PAG) and I aint got time to fully explain but suffice to say Japan and the States have not even produced much equipment using R407C but have jumped straight onto the long term R22 replacement, R410A. Unlike the blended R407C, R410A is a mono refrigerant and is well suited to small/commercial type systems, but R410A operates are a much higher suction and discharge pressure, so you cant retrofit R22 to R410A.

The other problem is the development of R410A in larger systems, R410A is not being used in large capacity systems with big compressors, the feeling of the industry seems to be a revert back to ammonia, R134A or in some cases R404A. Or the other alternative multiple smaller chillers piped together.

The other consideration is the type of compressors being used, we are replacing lots of old open drive R22 machines now with inverter driven and scroll compressors, this doesn't have anything to do with the refrigerant but companies are being encouraged to install new equipment which is energy effcient. Some of the system we install are eligable for enhanced capital allowance.

HTH, if you need any info or some free advice, feel free to give me a call at the office.

Ian