TABLE OF CONTENTS The most radical revolution that the refrigeration and air-conditioning industry has experienced is probably the one that began a few years ago with the phase-out of chlorofluorocarbons (CFCs). After having about 50 years to develop and learn to properly apply a certain assortment of refrigerants, the industry needed quickly to replace some widely used refrigerants. Manufacturers of domestic refrigerators and auto air conditioners, for example, have been forced to find a substitute for R-12, which has been used effectively in those products for many years. The industrial refrigeration industry had settled primarily on the use of two refrigerants ammonia and R-22. A third refrigerant, R-502, which is a dominant refrigerant in supermarket refrigeration and other commercial applications as well as occasional industrial applications, is scheduled for retirement.
The premise of this chapter is that ammonia will continue to be a dominant refrigerant in the industrial refrigeration field. Also, the halocarbon refrigerant that is most prominent in the industrial refrigeration field, R-22, will be vitally important for the next several decades until it is discontinued. R-502 will be phased out because it contains a CFC. A crystal ball is needed to predict which halocarbon or halocarbons will eventually replace R-22 and R-502. A few industrial refrigeration systems used R-12, but most of these systems have been retired by now. If the system served moderate-temperature evaporators, R-134a could serve the application. In fact, the most successful replacement so far has been of replacing R-12...
