Refrigeration unit advice

[makingplansfor]

I am converting a coolbox to freezer and have decided upon a water cooled system. I particularly like the Isotherm units as they seem to provide better value than others e.g. frigoboat. I would like to hear thoughts of people who have lived with theirs, in particular, the effectiveness of the heat exchanger embedded in a through hull and the self pumping of refrigerant. The experience of those using the unit in tropical climes will be particularly valued. Thanks

 

[vyv_cox]

I do not have that system but a friend with the same boat has one. He also keeps his boat in Greece, sea temperature up to 30C on occasion, and reports that it works very well. It was installed by him years ago. I have a photo of the cool box (not here) showing heavy ice on the cooler unit.

 

[Ian_Edwards]

I've just taken a Frigoboat keel cooled refrigerator out, I had a series of leaks in the pipework to the cooling pad on the outside of the boat, in essence a sintered bronze? block. The system was 12 years old, and it could of course be a function my particular installation, but I decided that it was more trouble than it was worth. the instructions say that the block shouldn't be anitfouled, but I found that barnacles loved it and it was totally covered with them after 6 month in the water, that made me wonder how effective it was as a cooling device.
I replaced with a Dometic, dual power system which runs off both 12volts DC and 240v AC and automatically switches to AC when it is present, so it will run of the marina supply or the generator.
I added an extra layer of insulation in the form of foil wrapped bubble wrap:
Thermawrap General Purpose Foil Wrap Insulation 1000mm x 7m -7m2 | Wickes.co.uk
mainly because I some in the garage at home, and because it isn't too bulky.
The Dometic was much cheaper than the Frigoboat equivalent, and seems to work well.

 

[superheat6k]

If you can make it water cooled then bear in mind 30oC water supply to the condenser equates to an air supply temperature for a similar capacity air cooled condenser ~ 20oC, so is actually very effective.

 

[makingplansfor]

I've just taken a Frigoboat keel cooled refrigerator out, I had a series of leaks in the pipework to the cooling pad on the outside of the boat, in essence a sintered bronze? block. The system was 12 years old, and it could of course be a function my particular installation, but I decided that it was more trouble than it was worth. the instructions say that the block shouldn't be anitfouled, but I found that barnacles loved it and it was totally covered with them after 6 month in the water, that made me wonder how effective it was as a cooling device.
I replaced with a Dometic, dual power system which runs off both 12volts DC and 240v AC and automatically switches to AC when it is present, so it will run of the marina supply or the generator.
I added an extra layer of insulation in the form of foil wrapped bubble wrap:
Thermawrap General Purpose Foil Wrap Insulation 1000mm x 7m -7m2 | Wickes.co.uk
mainly because I some in the garage at home, and because it isn't too bulky.
The Dometic was much cheaper than the Frigoboat equivalent, and seems to work well.

Thanks - I have largely ruled out the sintered bronze type of heat exchanger on the same logic. I have a ground plate made of the same material and the sea beasties love it!! Do you have the through hull type that f condenser or have you gone for air cooled??

 

[dslittle]

I am converting a coolbox to freezer and have decided upon a water cooled system. I particularly like the Isotherm units as they seem to provide better value than others e.g. frigoboat. I would like to hear thoughts of people who have lived with theirs, in particular, the effectiveness of the heat exchanger embedded in a through hull and the self pumping of refrigerant. The experience of those using the unit in tropical climes will be particularly valued. Thanks

We have a Frigoboat keel cooler for my freezer (that was a cool box). It has worked perfectly for the last five years in the warmish waters of Southern Brittany (air temps have got up to the mid thirties). Contents stay well below -10C with low Amp usage. We also had a spill over fan fitted to cool the fridge so we have redundancy on the air cooled fridge if needed. We do move around a lot when we are sailing and the boat is on the hard overwinter so we have never had a problem with nasties attaching themselves. The anodes are quite small and I do replace them every year but that is the only ongoing expense that we’ve had. We had it fitted by Rob Wells (who is quite well known on here) and I would thoroughly recommend it and him.

 

[RupertW]

If you can make it water cooled then bear in mind 30oC water supply to the condenser equates to an air supply temperature for a similar capacity air cooled condenser ~ 20oC, so is actually very effective.

And as well as that you aren’t heating up the cabin and it is far far quieter without the need for a fan.

 

[michael_w]

My keel cooled Frigoboat has kept my beer frosty cold when the water and air temperatures were 30c. Admittedly on a 50% duty cycle.

 

[geem]

I loved the Frigoboat keel cooled fridge on the last boat. Yes barnacles loved it but it made no difference to the performance

 

[vyv_cox]

My fridge is seawater cooled on a 'once through' basis using a Par Max 1 pump running on 6 volts via an Isotherm voltage reducer. The condenser is custom made, a very simple device in copper tubing. The fridge is now 17 years old, used non-stop for 6 months every year. The only problem has been that the cam in the swash plate of the original pump wore out and occasional shell fouling in the inlet hose. Fridge runs about 30% of the time, drawing 3-4 amps.