Frigoboat Keel Cooled Fridge/Freezer

[Mjstep]

Hi All, we are looking to hear people's experience with a Frigoboat Keel cooled fridge/Freezer system on their boats in warm waters. Our boat came with a 15 year old Frigoboat freezer with spillover fridge and we are finding it's difficult to get below 28 degrees F and consumes A LOT of power.

We are interested in hearing how low you can get your freezer in warm waters (can it get down to 0 degrees F)? What is it's typical energy consumption? And do you have a spillover fridge or two compressors?

We did recently find the merlin circuit board was corroded when the freezer started rising to 45 degrees, so we removed it. We still need to get a new merlin to see if that solves our issues.

In the end, we are currently trying to decide whether to continue with our current setup or just switch over to a new system (would rather not spend the $$$). Thank you!

[Rascally]

I have two BD-35 Frigoboat keel cooled systems; fridge and freezer.

While I don’t have the knowledge or experience of a qualified tech, I’ve learned that these systems are worth keeping, and just need setup correctly. These are great performers, and if setup correctly, consume little power. My freezer is one such example… Draws 3.5 - 4 amps, but does run more than it should; not the compressor’s problem, but is the limited insulation of my freezer box.

My fridge on the other hand, it’s terrible. I cannot find anyone qualified to setup the gas properly. There seems to be a disconnect, where the keel cooled model is not fully understood by the tech’s. I do know where to find a tech that knows what to do, but I won’t be back there until July.

Thus, I’m about to dig in and learn the craft. I’ve noted the manufacturer’s advice to use basic quality gauges and pure R134a gas. The manufacturer offers a description of how to setup the the gas pressure (which isn’t about pressure really), and I’ve noticed that all the Techs I’ve hired don’t follow the instructions, even though I’ve provided the documentation and advised that all I want them to do is simply follow the manufacturer instructions. Rather, they rely on their training regarding pressure values; so my fridge is running like crap.

The key to successful keel cooling is to understand that you cannot treat the system like a typical fridge system. So says the manufacturer’s instructions.

So, I believe that one day my fridge will work as well as my freezer, but for now it’s not.

I have no intention to replace a perfectly good system.

Keel cooling works in the warm Caribbean waters, as my freezer is just awesome. Wonderfully below zero. I guess it’s about -10 to -14C.

[hycslim]

Hi

We have had a Frighted o Boat keel cooler with the spill over fridge freezer on our boat since 2018. In that time we have spent two winters in the Bahamas and haven't had any issues with keeping things cold or frozen. We set the fridge at 38F and the freezer at 15F, this keeps the beer nice and cold and frozen goods nice and solid. I do find it important to make sure that the air flow from the thermostatic fan isn't impeded. We draw around 5 amps after a shopping trip, once things cool down we draw 3.5-4 amps. The only thing I would have done differently would have been to buy a unit that allows air cooling as an option when on the hard.

Good Luck

Allan

[Rascally]

An update… I’ve just checked my freezer temperature.

-18C to -24C, depending on where I place the probe. I’m sitting at Charlotte Amalie, in water that is probably 82-84F°. Suffice to say, keel coolers work just fine. They just need to be setup correctly.

[RaymondR]

"The only thing I would have done differently would have been to buy a unit that allows air cooling as an option when on the hard."

I've had an Ozefridge eutectic system running for about the last 18 months that has that capability, it works well. However they recommend that the cooling water be from the fresh water tank rather than raw water. Since the condensing system only runs once or twice a day there's plenty of time for the fresh water tank to return to ambient.

[GordMay]

Originally Posted by Rascally

... Keel cooling works in the warm Caribbean waters, as my freezer is just awesome. Wonderfully below zero. I guess it’s about -10 to -14C.

According to the US FDA & USDA*, “The freezer temperature should be 0° F (-18°C), or below.” [to a maximum of about -23°C/-9°F]
* ➥ https://www.fda.gov/consumers/consum...ng-food-safely
Whereas: your freezer is only reaching -10°C = 14°F, or -14°C = 6.8°F.
Not “awesome” - barely adequate, if that.
How is your ice-cream?

[Rascally]

Originally Posted by GordMay

According to the US FDA & USDA*, “The freezer temperature should be 0° F (-18°C), or below.” [to a maximum of about -23°C/-9°F]
* ➥ https://www.fda.gov/consumers/consum...ng-food-safely
Whereas: your freezer is only reaching -10°C = 14°F, or -14°C = 6.8°F.
Not “awesome” - barely adequate, if that.
How is your ice-cream?

So, that was my “I’m not a scientist guess”. But then, my comment about ten minutes later, is awesome. 😎

[GordMay]

Originally Posted by Rascally

So, that was my “I’m not a scientist guess”. But then, my comment about ten minutes later, is awesome. 😎

I, humbly, stand corrected.

[s/v Jedi]

Your problem isn’t the compressor, it is the box. Such high power consumption indicates failed insulation, it’s probably soaked with water originating from condensation.

I have done a full rebuild and 20 years later found that it wasn’t worth it because it again got wet (not as much but still…) and the amount of work is staggering.

The Frigoboat keel coolers have been troublesome. I had three and wished I would have used air cooled instead. In the end I was forced to switch to air cooled as all three keel coolers had failed.

I decided to remove everything and modify the cabinet to accept a SnoMaster stainless steel mobile chest unit instead. I ended up with three of those units and never had problems again. When they wear out, I simply buy a new one and drop it in

[Tupaia]

I have a 4cu ft freezer with BD50 and a biggish bar fridge with a BD35. Both run keel coolers that were replaced after 24 years due to barnacle damage and I was in a place where I could. The compressors are original.

The freezer top loading has 150-200mm insulation all round and 350mm in the bottom sits at -19C (enough to keep Magnum ice creams) and draws about 20amps per day in tropics. 2-3 days to defrost if switched off. Insulation is the key to low power consumption.

The fridge, various converted domestic units, (replaced 3x in total) front opening but top spec insulation sits at 4C and draws between 24 and 30 amps per day in the tropics.

Only maintenance is anode replacements. The fridge conversions have involved replacing the quick fit seals and you can no longer use the standard R600 filled plate that comes with domestic fridges. So I transfer the old plate that uses R134a. Too much or too little gas leads to either insufficient cooling effect or freezing of the transfer pipes.
The small bullet driers fitted as standard are often the cause of oil getting into the system especially if the runs are quite long. I have replaced them with small beer can sized A/C system driers.


I don't like the fridge / freezer cascade arrangement having separate units is much better.