Removing Excess Moisture from Refrigeration Systems

Am I missing something here? why not a vacuum?

I would say compressed air blow it out.

......not compressed air.............that has water in it...............once repaired you blow dry nitrogen through the system.

Before system evacuation and charging, you could fit a large adsorbent (not absorbent) filter drier in the system.

By the way in Australia you have to be certified to work on any refrigeration system.

..........nice to know people still pollute the atmosphere with HCFCs.

OK, there is a lubricating oil in the system. This has to be removed and the system flushed with an acceptable solvent until it is clear of all the old freon and water and oil.

Some parts might be damaged/corroded by the water, so refer to the maker for guidance. You might need to replace some mechanical components. There are components called 'inline dryers' installed from before. They need to be replaced or baked out in vacuum (if possible).These dryers have a chemical water absorber and are freon tolerant. Suggest you ask the maker.

You then draw a vacuum on the system and recharge it with the proper amount of freon and lubricant into the compressor sump. This is a routine task for a refrigeration mechanic. They know the details. What I gave you is an outline. You may be wise to hire specialists. The system might have a leak on the low pressure seal side and draws in air with water? This gradually decrements the efficiency of the circuit and if the water dryers get saturated you can have free water circulating as ice or fluid. Ice is abrasive and water is not conpressible and enough can blow the heads off your compressor when it tries to compress water liquid(which it cannot do)

Hi aurizon,

.....chemical water absorber and are freon tolerant.

I think, that as you pointed out, the absorbent driers are a better option than the adsorbent driers, as they can hold a large volume of water. Once the system is proved to be thoroughly "dried out"............then install the adsorbent driers.

After major work, as this obviously is, it is a good idea to install a 10 micron felt core filter on the suction line to protect the compressor from damage..........once the system is thoroughly clean, this filter can be removed.

All these filters are and driers are in-line............on larger systems you can also have by-pass filters fitted.

How about hot N2, followed by pulling a vacuum like you normally would have to do. You can set up a test (I think it is called a chandler test) to test the system for moisture once you think you are close and it will ballpark your dewpoint for you

I have been there

You will need multiple vacuum pumps and lots of pump oil, and even more patience.

Keep an pulling a vacuum until the oil stops turning milky white. You will be changing the oil several times a day, for many days.

I suggest you look up methods of moisure removal in your refrigeration manuals.

Try using a high capacity vaccuum pump with a trap piped between the compressor and the vaccuum pump. Wrap the trap in dry ice and insulate. This will trap the water before it fills your vaccuum pump.