I have a YORK Home A/C unit that needs Freon R-22. I have both the hoses and the Freon. My question... When I hook my hoses to the Hi and Lo pressure ports, do I need to have the unit "running" to check the pressures ordo I check it "static"? When adding Freon, Do I have the Unit running when Recharging? Do I add the "Liquid" phase or the "Vapor" Phase. Which is the best port to add the refrigerant... Low Suction port or the high Condensing
Port? Is there a good book available that I can brush up on the techniques. I know a little about how the A/c's operate, as I have recharged AUTO systems in the past. I do have a Vacuum pump and a recovery tank.

Thanks,
Wayne

To charge the unit it needs to be running, and you will charge it into the low pressure suction side, which will be the blue gauge on your set of gauges and it is best to add the gas instead of he liquid. Do you know how to charge the unit to get the pressures right?? If you are not certified to handle freon then you should not let anyone know what you are doing, there is a $25,000 reward for turning in people breaking the law, and they don't have to prove that you did it you have to prove that you didn't do it.