The quality and quantity of waste heat available for recovery depends upon the operation of the
refrigeration system. The temperature of the compressor discharge gas determines the quality of the
waste heat. This temperature in turn is dependent upon the temperature of the return gas at the
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compressor suction header. The compressor discharge temperature is also affected by the saturated
condensing temperature. As the condensing temperature decreases, the discharge temperature
decreases. The optimum conditions for operating the refrigeration system, i.e., operating at the highest
suction pressure and lowest condensing pressure, leads to the minimum amount of available waste
heat. However, it is much more effective to operate the refrigeration system at its most efficient
conditions with a minimum amount of waste heat than it is to operate the refrigeration system less
efficiently in order to produce more waste heat.