Wondering about a unit for my 1996 Hunter 376 It has a split ice box. I believe an auxillary fan is used to move cold air between the 2 boxes. We cruise on Lake Superior where the water temperture does not rise above 60 degrees F. Would a water cooled unit be more efficent. Would appreciate insights on model, installation and nuances of the system Thanks
Retro for Hunter 376
- Thread starter Mark Juetten
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Try Air 1st
I have a 1984 Hunter 34 in Fort Myers Beach with an air/water cooled frig. The water pump has been a hassle. It has burnt out twice in 6 years and lost prime I many times. It quit again and I'm going without as a test. the first few times (a 10 day sail and a 3 day sail) we noticed almost no difference. The water here is over 80 degrees and the air temp is from 70-90 (night and day). Say the pump uses 1 amp per hour and the frig runs 8 hours per day then you use 8 extra amps to run the pump. Without the pump your frig may run 10 hours per day which may only use a few amps more than the water cooled unit. I'll be interested in hearing other experiences.
I have a 1984 Hunter 34 in Fort Myers Beach with an air/water cooled frig. The water pump has been a hassle. It has burnt out twice in 6 years and lost prime I many times. It quit again and I'm going without as a test. the first few times (a 10 day sail and a 3 day sail) we noticed almost no difference. The water here is over 80 degrees and the air temp is from 70-90 (night and day). Say the pump uses 1 amp per hour and the frig runs 8 hours per day then you use 8 extra amps to run the pump. Without the pump your frig may run 10 hours per day which may only use a few amps more than the water cooled unit. I'll be interested in hearing other experiences.
Water cooling question
Water cooling these small refrigeration systems is a mistake for many reasons, pump failures, pump air locks, screen clogging, additional amperage is required over air cooled, and total destruction of a system when the seawater inters the refrigerant circuit. For additional information on this subject see FAQ #33 on my web site. http://www.kollmann-marine.com
Water cooling these small refrigeration systems is a mistake for many reasons, pump failures, pump air locks, screen clogging, additional amperage is required over air cooled, and total destruction of a system when the seawater inters the refrigerant circuit. For additional information on this subject see FAQ #33 on my web site. http://www.kollmann-marine.com
water cooled refrig
I have a cold plate system. Water cooling was added about 2 years ago. The run time has been reduced significantly. It takes abount 1 hour to bring the box down to 30' and shut off. With air cooling it never shut off and the heat that dissapated off the air cooled condenser raised the cabin temp considerably. This is in South Florida where its 90'+ in the summer. I just had a water pump go out. I found a simple solution-used a bait tank pump-pumps 600gph(rated) raises the water high enough, can run dry and was $30. Cheap enough to by a spare. I can't keep ice cream, but the system keeps the food cold for 25 hrs.
I have a cold plate system. Water cooling was added about 2 years ago. The run time has been reduced significantly. It takes abount 1 hour to bring the box down to 30' and shut off. With air cooling it never shut off and the heat that dissapated off the air cooled condenser raised the cabin temp considerably. This is in South Florida where its 90'+ in the summer. I just had a water pump go out. I found a simple solution-used a bait tank pump-pumps 600gph(rated) raises the water high enough, can run dry and was $30. Cheap enough to by a spare. I can't keep ice cream, but the system keeps the food cold for 25 hrs.
Go with a water cooled holdover plate system
They are the most expensive and by far the most effecient. Of course it is important to know how many cubic feet your box is in order to give you the best advice on exactly which system will work the best. I would only use a water cooled D.C holdover plate system in a sailboat if your budget permits. Grunert makes some very nice systems.
They are the most expensive and by far the most effecient. Of course it is important to know how many cubic feet your box is in order to give you the best advice on exactly which system will work the best. I would only use a water cooled D.C holdover plate system in a sailboat if your budget permits. Grunert makes some very nice systems.
Isotherm
Just finished rebuilding my frige box and installing new water cooled Isotherm setup. I could not be happier! The air cooled setups work fine in colder climates but when the weather warms up the holding plate and water cooling are king! Any fool knows that water can absorb more heat at a faster rate that air. Best of luck. Jamie
Just finished rebuilding my frige box and installing new water cooled Isotherm setup. I could not be happier! The air cooled setups work fine in colder climates but when the weather warms up the holding plate and water cooling are king! Any fool knows that water can absorb more heat at a faster rate that air. Best of luck. Jamie
tiger 37373, Maybe not so foolish
Most boaters would prefer a reliable refrigerator; the small water-cooled unit you installed can not be counted on for extended or continuous operation. Check some of the Forum archives and you will see the how these systems perform. 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 BD compressors is a mistake for many reasons, pump failures, pump air locks, screen clogging, additional amperage is required over air cooled, and total destruction of a system when the seawater inters 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 degrees 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 do to electrolysis corrosion and this allows seawater to mix with the refrigerant and destroy the complete system. If you are a weekend sailor, and don’t leave the refrigerator on while at the dock, and don’t have an onboard generator, you could have good success with your system, if you stay in the seawater temperatures around San Diego.
Most boaters would prefer a reliable refrigerator; the small water-cooled unit you installed can not be counted on for extended or continuous operation. Check some of the Forum archives and you will see the how these systems perform. 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 BD compressors is a mistake for many reasons, pump failures, pump air locks, screen clogging, additional amperage is required over air cooled, and total destruction of a system when the seawater inters 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 degrees 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 do to electrolysis corrosion and this allows seawater to mix with the refrigerant and destroy the complete system. If you are a weekend sailor, and don’t leave the refrigerator on while at the dock, and don’t have an onboard generator, you could have good success with your system, if you stay in the seawater temperatures around San Diego.
Isotherm
I am using a Isotherm unit all year long on my 35.5 north of Dallas, Texas. I set it up with the holding plate in the freezer side and move air with small fans into the refer side. Uses the water flowing into the sink drain thru hole. I also freeze ice for my drinks.
I am using a Isotherm unit all year long on my 35.5 north of Dallas, Texas. I set it up with the holding plate in the freezer side and move air with small fans into the refer side. Uses the water flowing into the sink drain thru hole. I also freeze ice for my drinks.
Frigoboat
Don't need pumps and even does away with the cooling fan for the heat exchange coils. Just a little vibration from the compressor. No noise, no hot air. Uses less energy and in your climate and water temperature, it should be ideal. S/V Anodyne Catalina 36'
Don't need pumps and even does away with the cooling fan for the heat exchange coils. Just a little vibration from the compressor. No noise, no hot air. Uses less energy and in your climate and water temperature, it should be ideal. S/V Anodyne Catalina 36'
effeciency
Water cooled systems are alway more "effecient" than air cooled when the water temp is somewhat cooler that ambient air....the cooler the fluid (air or H2o in your case) moving over the condensor enables the compressor to work less hard..that is not to build up as high a head pressure....that takes horsepower and the more horsepower IN for the amt. of cooling produced...lowers the effeciency. However, you raise the level of complication as to the kind of system....holes in the hull, water pump, etc. If you sailed in the arctic and for some reason could not keep your stuff outside to stay cold....you might, of course, use ambient air to blow over the condensor...The water would be more dffecient simply because water can transfer more heat than air....but the outside air would be very cold so you wouldnt need water,,,,,,sorry if confusing ...
Water cooled systems are alway more "effecient" than air cooled when the water temp is somewhat cooler that ambient air....the cooler the fluid (air or H2o in your case) moving over the condensor enables the compressor to work less hard..that is not to build up as high a head pressure....that takes horsepower and the more horsepower IN for the amt. of cooling produced...lowers the effeciency. However, you raise the level of complication as to the kind of system....holes in the hull, water pump, etc. If you sailed in the arctic and for some reason could not keep your stuff outside to stay cold....you might, of course, use ambient air to blow over the condensor...The water would be more dffecient simply because water can transfer more heat than air....but the outside air would be very cold so you wouldnt need water,,,,,,sorry if confusing ...
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