puron,like all other refrigerants must be recovered because of the ''what if'' factor ,although there are no negatives against it as of now, 5-10-or even 15 years from now they might find out something bad about it.r-12 was the greatest thing to happen to the a/c world along with r-22,then they find out the damage it does to the ozone,,who knows,maybe they will find out down the road that puron causes a third arm to grow out of your nose..i install and service trane-carrier and york units along with some others.and trane seems to be the better built and most reliable...just my opinnion....ron
