Unifridge? Anyone have experience?

[Bigjim]

My Columbia 10.7 had a unifridge unit installed as optional equipment back in 1978. It has long since died.

Anyone have any experience or knowledge of what this unit does? It does not seem to have a compressor so I have no idea what value it would provide.

Someone is selling one on Ebay. Is it worth considering? Or would you suggest another alternative.

[OzePete]

Hi Jim,
Most likely it is a Peltier system. Extremely inefficient and would be virtually useless in most marine applications even if it did 'work' ! This refrigeration method will consume several times (up to 5 times!) more battery power than a 12VDC compressor unit and not achieve anywhere near the temperatures usually sought.
Cheers OzePete

[Bigjim]

Originally Posted by OzePete

Hi Jim,
Most likely it is a Peltier system. Extremely inefficient and would be virtually useless in most marine applications even if it did 'work' ! This refrigeration method will consume several times (up to 5 times!) more battery power than a 12VDC compressor unit and not achieve anywhere near the temperatures usually sought.
Cheers OzePete

Do you have a system you recommend for a 35ft boat? My plans are to do some extensive cruising in a couple years.

[OzePete]

Originally Posted by Bigjim

Do you have a system you recommend for a 35ft boat? My plans are to do some extensive cruising in a couple years.

Hi Jim,

We would be able to supply a system package specifically to suit your cabinet but firstly we would need the following information:
A: Cabinet interior dimensions. Width, Depth and Height.
B: Cabinet wall thickness if possible.
C: Cabinet lid / door opening dimensions. (advise if lid or door)
D: Cabinet inner lining material. (Is it metal or not?)

We would put this data into our Heat load & Duty Cycle estimator to enable us to recommend a system that will provide adequate refrigeration in all environments along with daily power consumption and duty cycle calculation.

BTW, this fridge cabinet Heat load & Duty Cycle estimator service is offered freely and without any obligation to all CF members regardless of system type being used or to be used. Members can simply email answers to the questions above if an estimate is required. (Click on chart sample below to expand)



Cheers, OzePete Ozefridge | 12 Volt Refrigeration Systems

[gmakhs]

Peltier system can work if you find a way to extract the heat , I am experimenting on a water cooled one until now has good results.but didn't have the time.test it real time.

[a64pilot]

Peltier is cheap and simple.
They are also horribly inefficient, if you get one big enough to cool a box, it will draw at least three times the power of a compressor.
There is a reason why you only see them on cheap box coolers.
I had one onetime, Coleman, it would only hold about a 20 degree temp difference, and that only if whatever you put in was cold to start with, so on a 95 degree day at the race track, it would hold your Gatoraid about 75 degrees.
Better than pee warm, but not much.

[gmakhs]

My peltier unit can reach -10 celcious with 30 deegress outside , I believe once I finish the set up it will.work , the consumption is 2 ah .
Not better than the compressor unit but it cost me.25 euros for.all the parts .

[a64pilot]

If you look up Peltier plate efficiency, I did cause I was curious, you’ll find that it is 1/4 as efficient as a typical vapor cycle compressor.

https://en.m.wikipedia.org/wiki/Thermoelectric_cooling

[SV THIRD DAY]

We just took that system out on my son's Columbia 10.7....
It is a Peltier system, which will pretty much kill your battery bank, so our torn out unit when in the trash.

[Cadence]

Originally Posted by Bigjim

My Columbia 10.7 had a unifridge unit installed as optional equipment back in 1978. It has long since died.

Anyone have any experience or knowledge of what this unit does? It does not seem to have a compressor so I have no idea what value it would provide.

Someone is selling one on Ebay. Is it worth considering? Or would you suggest another alternative.

In 1978 I doubt it was a Peltier. Probably an absorption unit. They are efficient since about any heat source can be used. You will hear being level is a must? To some degree. By all means do not, do not crack the charge port to see if it is charged.

[Dooglas]

Originally Posted by Cadence

In 1978 I doubt it was a Peltier. Probably an absorption unit. They are efficient since about any heat source can be used. You will hear being level is a must? To some degree. By all means do not, do not crack the charge port to see if it is charged.

I'm not aware of absorption refrigeration being successfully used on a sailboat. Yes, leveling is definitely an issue - but even more important, what would be the source of the heat? Propane is most commonly used in RVs. Heating with 12V electricity would be very inefficient.

[Copacabana]

Originally Posted by Dooglas

I'm not aware of absorption refrigeration being successfully used on a sailboat. Yes, leveling is definitely an issue - but even more important, what would be the source of the heat? Propane is most commonly used in RVs. Heating with 12V electricity would be very inefficient.

Actually, the PO of my boat installed a propane fridge in the boat (Dometic) which worked very well until I replaced it with a new Engel drop-in fridge. It was gimballed, though I hardly ever used the gimbals (it was normally locked in place). I got close to a month of use out of one 13kg propane tank. The only drawback was that it was vented inside the cabin (but almost under the companionway) so it did heat up the cabin a bit here in tropical Brazil. In a cooler climate, I think it would be fine.

[Boatguy30]

I had a 35' mono-hull Wauquiez Pretorien. Had a gas fridge installed near the centerline of boat when I bought it with door facing forward. Previous owner had circumnaviated with it and said it worked great. My insurance company at the time required me to remove it and I never tried to use it. With current solar prices, I think DC is cheaper than buying all the propane.

[Dooglas]

Hmmm, given the cost, availability, and safety considerations of propane powered refrigeration on a boat - I'm wondering why anyone would not choose compressor refrigeration using an efficient system such as the Danfoss compressor. I've had great results with the Isotherm AC/DC refrigerator/freezer unit in my Uniflite, which replaced a less efficient older Norcold unit.

[Copacabana]

Originally Posted by Dooglas

Hmmm, given the cost, availability, and safety considerations of propane powered refrigeration on a boat - I'm wondering why anyone would not choose compressor refrigeration using an efficient system such as the Danfoss compressor. I've had great results with the Isotherm refrigerator/freezer unit in my Uniflite, which replaced a less efficient older unit.

Yes, that's why I changed it out for an Engel fridge. With solar panel prices today, it just makes more sense to go electric. That said, I didn't worry too much about the safety of the propane fridge (I have a propane stove and BBQ after all), but I never left it on when I left the boat for more than a few hours, just in case...