Refrigerant Charging! Checking the R-22 Refrigerant Charge on AC Condensor! Subcooling Method!

This is how to check a refrigerant charge using the subcooling method of charging. This is for comfort cooling systems when residential and commercial systems have a thermostatic expansion valve. The outdoor unit will have the required subcooling rating desired on the rating plate and as long as you are within + or - 3 degrees then the charge is correct. I like to have a slightly higher subcooling rating so that there is an extra degree or two of subcooling which could get lost over time due to servicing and checkups.