Flash Gas
When we say that there is “flash gas” at a particular point in the system, it can either be a bad thing or a good thing, depending on where it is occurring. Flash gas is just another term for boiling. It is perfectly normal (and required) that refrigerant “flashes” or begins boiling directly after the […]
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What Should My Subcooling Be?
  This is the article you read BEFORE you call and ask a senior tech what your subcool should be. It's also the one you send to a junior tech when they call and ask you: So, what is subcooling? (Or subcool, as many call it.) Subcooling is a measurement of temperature DECREASE of a […]
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Know the Limits of Subcooling
This article was written by RSES CM and excellent market refrigeration tech Jeremy Smith. Thanks, Jeremy! I frequently see techs online struggling with charging or troubleshooting refrigeration equipment and using subcooling as a diagnostic or charging method. Please don't do this unless you understand it fully. Many times, trying to charge a refrigeration system to […]
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The “5 Pillars” of Residential A/C Refrigerant Circuit Diagnosis
Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]
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Subcool and Liquid Line Length
The primary role of setting an appropriate level of subcooling is to ensure that we deliver a full line of liquid refrigerant to the metering device. We want to do this at: A pressure differential required by the metering device At a temperature and pressure no higher than required for maximum capacity and efficiency But […]
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