The air-conditioner is not cold when turned on? Saw some ice forming on the indoor/ fan coil unit when in operation? These are some of the symptoms that your air-conditioner is shortage of refrigerant/ gas.
Air-conditioner refrigerant system operates in a closed cycle. Minor refrigerant top up may be required after years of usage. In cases whereby your air-conditioning system required refrigerant top up/ refill frequently, this could indicate that there is a leakage in the refrigeration system.
To check for refrigerant leakage, there are generally 2 levels of checking.
- Visual Checks
- Pressure Test (Thorough Checks)
For visual checks of the refrigerant system, technician will first refill the refrigerant for the air-conditioning system, and do visual checks to look out for any oil stains at flare nuts (Joint Connections), oil stains at condenser and fan coil units. The technician will also use soap bubble test to check on all the joint connections to look out for refrigerant leakage. Customer will be asked to monitor if the problem still persists after the visual checks are completed.
The following video shows so that a leakage was found at the flare nuts through soap bubble test.
Soap Bubble Test At Indoor Unit Flare Nut
Soap Bubble Test At Condensing Unit Flare Nuts
Please note: Visual checks is not a 100% check, it is a faster, and least expensive methods use for checking refrigerant leakage.
To have a complete check for refrigerant leakage, it is recommended to do a pressure test for the entire system. Pressure test will require minimum 3 working days to complete in order to obtain accurate results. Technician will used nitrogen gas and pressure gauges to hold pressure on each parts of the refrigerant system, namely the indoor/ fan coil units, the compressor/ and the individual piping. Markings will be made on the pressure gauges after it is being pressurised to the required testing pressure with nitrogen gas. Technician will return 3 working days later to check if there is any dropped in pressure. A drop in pressure will indicate that there is a leakage point. Rectification work will then have to be performed.
The following photo shows how pressure test is being performed.