Mel's Note Card Holder  
Tom and Mel... achievable cruising under sail and power.


Cooling Cures
by Tom Neale

This is a continuation of Tom's Tips from his section of the web site. Go to his section there for many more tips on this subject and others.

1. Never bend the copper tubing that transports the refrigerant, unless you are using proper bending equipment. This can crimp the tubing and hinder passage of refrigerant and this can damage the compressor. Attempts to straighten out the crimp will often make it worse. Sometimes this will occur accidentally when people are working around the lines. Make sure any mechanic working on your boat knows where these lines are located.

2. If a refrigerator or air conditioning compressor has a raw water heat exchanger, this may be the reason for diminution or total loss of cooling. You'll know if yours has a water heat exchanger by the coil of tubing on or near the compressor and the fact that a water pump will be pumping water from a through-hull to the tubing. Usually marine air conditioning units and larger refrigeration compressors use this system. Of course, you already know that if your strainer or through-hull intake is clogged, or if your pump is defective, you've got a problem. But also remember that, in time, the inside of the cooling tubes may have deposits build up on them, of sufficient thickness to impair the heat exchange. Depending on the type of metal in the coil and in the refrigerant tube that passes through the coil, there are various products that you can pump through the heat exchanger coil to clean it. Consult with the manufacturer to learn what works for your unit. This is often a job that you can do yourself. Smaller units, such as dedicated ice makers, may be cooled simply by a fan moving air over fins. If you have fan cooling, check to see that no dust or other obstructions are interfering with the air flow over the fins, and, of course, that the fan is operating. (Careful of your fingers.)

3. Whenever you add refrigerant to a compressor be sure you're adding it to the correct port. If you add it to the high pressure side, you could cause the can to explode with devastating effects. Check with the manufacturer to be sure that you know which port to use.

4. In all cases, disconnect power source unless you must run the unit, and then be careful of dangerous electric shock.

5. I'm not a refrigeration mechanic and you should take these only as general comments about things that I've observed as a layman who's had to deal with refrigeration gone bad while out cruising and who doesn't like spitting cockroaches.

Copyright 2004
Tom Neale


Previous Tips from Tom