How can determine if I have enough Freon in the system? Someone told me if coolant pipe is not very cold then there is not enough Freon. Is it true?

TG

To do the job correctly you will need a set of wet and dry thermometers to determine the inside temp and humidity. Then you will need a set of regular thermometers to check the air in air out of the condensing unit and liquid/suction line temperatures. Then you will need a set of gauges to check the high side/low side pressures.

After you have all the readings then you will be able to figure out if the subcooling/superheat is correct for the unit.

Some units have a label posted on the outside unit that will tell you what the charge is. If that is the case you will need a recovery machine and recovery jug. Then you remove all the freon (refrigerant) as you call it and then weight in the exact charge.

The method you mentioned is the beer can cold method and it never worked it was just a rumor for the uninformed.

hvac1000 is 100% correct. If you try to charge it so the suction line is real cold, you will probably over charge it and that will destroy your compressor.