NUREMBERG, Germany — While the air conditioning sector still debates R-410A or R-407C as the alternative to R-22, the refrigeration sector has long signed off on two choices: R-404A and R-507.

The stateside tilt has been toward 404A. In Europe, much more ado has been accorded 507.

The latest high-profile placement of R-507 is at Ford’s Engineering and Research Center in the United Kingdom. York recently brought on-line one of the largest vehicle testing facilities in the world. The compound screw compressors were charged with 507 as sold to York by Honeywell under the brand name AZ50.