Moisture In the System

COMPLAINT--Cooling is not adequate during the hot part of the day, but may be satisfactory during the early morning or late evening.





Condition
- The low side gauge reading normal but may drop into vacuum during testing.
- The high side gauge reading is normal, but will drop when the low side drops into vacuum.
- The sight glass may show tiny bubbles.
- The discharge air from the evaporator is cold, but becomes warm when the low side gauge drops into vacuum.

Diagnosis--Excessive moisture in the system. Desiccant agent is saturated with moisture which is released during high temperatures. The moisture collects and freezes in the expansion valve which stops the refrigerant flow.

Correction
- Depressurize the system.
- Renew the dryer bottle.
- Evacuate the system using a vacuum pump.
- Recharge the system with new refrigerant.
- Operate the system and check the performance.