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Old 04-06-18, 07:24 PM   #5
jeff5may
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You two are both correct.

Hugo says that only gaseous refrigerant should be leaving the evaporator. This is a hard rule. The metering device should never allow liquid refrigerant to find its way to the compressor. Liquid slugging is a leading cause of compressor burnout.

Zwerius said that the evaporator will follow outdoor temperature. To evaporate, the low side pressure must be low enough to allow the refrigerant to exist as a gas. What that means practically is the boiling point of the refrigerant has to be colder than the heat exchanger temperature. In an air hx, the boiling point must be a dozen or more degrees below the outdoor temperature, to insure at least a few degrees of superheat in the leaving refrigerant. In a water hx, the boiling point can be closer to the entering water temperature, because water has a lot more heat capacity than air.

Last edited by jeff5may; 04-07-18 at 05:13 PM.. Reason: Soelling and grammer
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