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Note 34. Refrigerants

A group of energy conservation measures in the Energy Efficiency Manual deal with the efficiency, maintenance, and environmental aspects of refrigerants. In addition, refrigerants play a role if a variety of the other measures that apply to cooling systems. This Note covers the main issues of refrigerant selection from the standpoint of the purchaser, the designer, and the operator of air conditioning, refrigeration, and industrial cooling systems.

You cannot select a refrigerant for efficiency alone. Selecting refrigerants has other major consequences, of which the main ones are environmental protection, toxicity, flammability, operating pressures (which affect safety and refrigerant leakage), and equipment size. Refrigerant selection is presently in a state of uncertainty because of environmental concerns about the most popular contemporary refrigerants.

This Note will enable you to understand the present issues of refrigerant selection, and it will help you to judge how these issues may evolve in the future. You will learn which materials act as effective refrigerants, and you will learn to decode the mystifying naming system for refrigerants.

Special attention is given to the halocarbon refrigerants, which are presently the most popular and the most controversial. This class includes the chlorofluorocarbons (CFC’s), the hydrochlorofluorocarbons (HCFC’s), and the hydrofluorocarbons (HFC’s). You will learn about refrigerant mixtures and azeotropes, which attempt to preserve the excellent refrigeration qualities of these materials while minimizing environmental damage. Ammonia and other refrigerants are also discussed.

Controversy about refrigerants centers on environmental concerns, especially global warming and ozone depletion. You will learn about the refrigerant ratings for global warming potential (GWP) and ozone depletion potential (ODP).

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Note 34. Refrigerants