A post earlier this year gave me an idea about 'upgrading' the fridge
cooling system on my
boat. The DB 50 was cooled by a coil thru which sea
water was circulated. I switched it over to fresh
water.
The
compressor is in the
engine room, along with a 85 gal
diesel tank and a water tank of similar size right beside it. By replumbing the
cooling coil I now use the water tank to cool the refrigerant. The freshwater exits the tank at the bottom, circulates thru the coil and is pumped back into the tank thru the top. I use the breather for the tank for the return.
This summer was the test as we cruised north of Desolation Sound for three weeks. The system worked flawlessly. I checked the temperature of the
fresh water tank a few times each day and found the temperature was generally only about 2 degrees centigrade higher than the
diesel tank next to it. This temperature varies according to how much motoring we do. At
anchor or while sailing it was around 23 degrees, and after a few hours of motoring it would reach around 37 degrees (about the same temperature as the
engine room). I didn't keep track of how often the
compressor cycled on and off, but I really didn't notice a difference.
Advantages:
-Two seacocks no longer needed, with all the advantages that entails-No need for the sea strainer, always a pain in the butt to clean and maintain.
-I now turn on the reefer a day before embarking on a
cruise, ensuring it is nice and cold when we load it without me worrying about seacocks left open when away from the
boat.
-The system seems to run more efficiently, no hard data.
-Fresh water less corrosive on the whole system than sea water.
Disadvantages:
-85 gallons less fresh water. The other tank holds around 130 gallons so this was not a problem on a three week
cruise - partly because we carry bottled fresh water for drinking.