This past year I was working on a story in which I asked contractors to comment on trends in refrigerants. I was doing so because so much of my writing in 2014 related to new directions for such gases. Some of the subject matter was the phaseout of HCFC-22, the move away from high global warming potential (GWP) HFCs to lower GWP versions, work on HFO refrigerants, and the move toward naturals such as CO2, ammonia and HCs.
While some contractors seemed to be getting into those arenas in terms of studying about them, taking classes, and even doing some installing and servicing, the most common situation through 2014 appeared to be contractors working with R-22, R-410A, and R-404A. That appears to be because the aftermarket aspect of our industry is so strong and there is a lot of that equipment out there.