RE: Water Cooled Big Mistake
On pleasure boats when the refrigeration compressors are larger than 1/6 Hour power the process heat is almost always removed by seawater. Water cooling these small refrigeration systems with 12/24 volt BD compressors is a mistake for many reasons; pump failures, pump air locks, screen clogging, plus additional amperage is required over air cooled, and total destruction of a system can occur when the seawater enters the refrigerant circuit. With the older model, fixed speed compressors there can be an improvement in efficiency when sea water temperature runs between 55 to 70¢ª F. On systems using the new Danfoss variable speed compressors, the added current required to drive a pump offsets the efficiency gained by running the compressor at a slower speed in most small boxes or cooler climates. There is one serious problem with using water cooling with the small Danfoss BD compressors, many of the small seawater condensers have failed due to electrolysis corrosion and this allows seawater to mix with the refrigerant and destroy the complete system. I devoted one section in my 12 volt book to this subject. If you want more information on seawater effects on refrigeration and energy to power it see FAQ #33 on my web page.
