Calling all carboneads , time to spill your guts! I was just wondering how the industry in general is going with R744 systems (mainly overseas, I'm in australia). Are there many systems going in? Are customers specifying Co2, or asking for price options? I know europe is installing quite a few but what about uk and us, are there any in tesco or walmart?
Is it costing more or less to install than standard racks?
How do you all approach the piping - sizing, load grouping - ring mains or individual stubs?
What setups are you guys seeing, just dx low temp? mt liquid overfeed? transcritical? One rack per store or split like a normal store over 2 or 3 racks?
What about temp and flow control - electronic or mech?
In aus both major chains are pretty interested, installing them where local councils require "green" initiatives. We have about 5 or 6 sites running to date, mostly all the same setup - each time fine tuning a little (sometimes going backwards - but hey ya gotta learn some how). Usually we run 2 cascade systems per store, all comps bitzer - low and hi stage, copper piping up to 7/8". Liquid recirc for mt and ht loads with akv valves expanding the r744 into dx coils in lt systems. Hi stage systems are standard 404a racks, some aircooled, some water cooled, controls are electronic as you can get (gotta love supermarkets ) but there isn't too much in the way of smaller gear rated to 40 bar, mainly all industrial gear - thats where you guys come in... What are you seeing/hearing in your neck of the woods?

Thanks in advance