1. Vacuum method
2. Flowing refrigerant methods
Vacuum method:
1. Connect the vacuum pump to the low side of the system,
2. turn the pump on,
3. and let it run for at least 30 minutes.
This will remove most of the air from the system.
4. Close the low side valve,
5. turn the pump off,
6. and disconnect the vacuum pump.
Flowing refrigerant method:
1. Connect a refrigerant recovery/charging machine to the system,
2. and turn on the machine.
3. The machine will automatically purge the air from the system.
Once all the air has been removed from the system, you can add new refrigerant and close the valves.
