I agree the environmental thing is what's driving the move toward CO2 refrigeration systems...especially in Europe where they are far ahead of the USA environmentally.
From our standpoint as refrigeration contractors and technicians, I believe we all must be keeping a close eye on what's developing in CO2 all around us. Most of the news about CO2 in this country is currently about the supermarket sector with many CO2 secondary and cascade systems being introduced.
I think the big change will come about as a result of the rather ambitious goals of brand name companies like Coca-Cola who has already announced they will be all CO2 by 2015.
http://www.thecoca-colacompany.com/p...y_coolers.html
This should be telling us in the field that CO2 based refrigeration will be showing up all over. Think about McDonalds, 7-11, Starbucks, etc. all switching over to CO2 within the next 10 years.
The big change for us is these CO2 systems aren't just another new refrigerant...they're essentially new systems which few, if not none, of us now have any clue as to how they work and therefore we can't service them without some training.
Certainly, Coca-Cola will be training their own people to service this new equipment, but what about down the road when True and Beverage-Aire start manufacturing CO2 units? I don't see anything in the works at this time to prepare us for that eventuality.
I feel we should be interested in CO2 and learn whatever we can about it before it lands at our feet.
Tim...For what it's worth, I started a thread on this a while back:
http://hvac-talk.com/vbb/showthread.php?t=454672