Air In the System

COMPLAINT--Cooling is not adequate.





Condition
- The low side gauge reading is constant and does not drop. The pressure should drop until the compressor cycles (thermostat control).
- The high side gauge reading is slightly high (or slightly lower especially if a large fan is used to substitute ram air).
- The sight glass is free of bubbles or only shows an occasional bubble.
- The discharge air from the evaporator is only slightly cool.

Diagnosis--Non condensables present in the system. Air or moisture present instead of a full refrigerant charge.

Correction
- Test the system for leaks. Test the compressor seal area very carefully.
- Depressurize the system.
- Repair the leaks, and if necessary renew hoses or units.
- Renew the dryer bottle, it is probably saturated with moisture.
- Check the compressor oil level.
- Evacuate the system using a vacuum pump.
- Recharge the system with new refrigerant.
- Operate the system and check the performance.