What is the lowest temp you can add freon?
Got a bet with a buddy!
Depends on the freon and the pressure/temperature differential, either the atmospheric pressure or the pressure of the system you are trying to fill into. I guess you can add at anything above the boiling point of the freon you are using, filling into an empty system or into the atmosphere. As the pressure differential decreases (the pressure in the system increases), you are going to need more heat. You have to be able to build more pressure/temperature in the fill bottle, than the system you are trying to fill into.
The boiling point is usually very near the lowest possible temperature/pressure mark on your gage for that particular freon. I think it's around -40F for freon 12.
I can fill at most any temperature, my filling station has a heater or I sit the bottle in a bucket of hot water.
Maybe the correct answer would be anything above the freezing point of the freon (F-12 -158 F I think) you are using. Technically you could use gravity to feed freon as a liquid.
if it was frozen you would have to use a spoon. LOL
Maybe the easiest answer would be to look at your low side gage, at the temperature equal to the low side pressure in your system and have your fill bottle above that temperature/pressure for that particular freon.
Clear as mud.