I have learned a great deal from this site, and have gotten great information re a Trane Voyager 20 ton RTU that i inherited- ( more on that in another thread).
my question is subcooling, and how to measure TOTAL sub cooling in terms of system performance and charging a system.
I was taught the "beer can cold" method and also 60/ 225 is normal gauge readings. plan on being more of an engineer when looking at these systems, mostly air cooled R-22 split and package units with a TXV.
I have read several threads on here and the opinions vary somewhat as to how to properly measure TOTAL subcooling.
The most popular form of measuring subcooling that i have see in terms of consistancy is discharge pressure at discharge service valve, convert to a temperature, take a temprature reading at the liquid line close to the expansion valve, subtract the two, and the resulting difference is subcooling.
As understand it, the preferred method is taking a liquid line pressure downstream of the condenser, and a temp reading by the expansion valve for proper subcooling, but that is not always feasiable.
What is the most effective method to measure subcooling in terms of proper system performance?