DC Fridge ?

C

Chriznat20

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Joined
Apr 19, 2005
RO Number
17066
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257
My 26' Sundowner comes with an icebox (read: by design, no refrigeration, you must add ice to it). The drain broke (old plastic from 1991) and there are no parts available anymore.

I looked at Norcold, Dometics, and Nova Kools. They are $569-$800.

I googled "DC refrigerator" and found this gem:
http://www.amazon.com/Avanti-Superconductor-Refrigerator-Black-2f-Stainless/dp/B0028MOZI6

Its an Avanti 1.7cu ft. AC/DC fridge and it costs around $169-$200. Comes with a cigarette plug. And it got good reviews on the web, primarily from OTR truckers, but also a few boaters.
Ironcally, I have an auxillary "cigarette lighter" type plug that I installed in my galley for our little 1 cup DC coffee pot, that runs right to the battery. So Im covered there. My boat does not have shorepower so it would run off one of my group 27 batteries.

Does anybody have experience with these? Any feedback on installing a 12vrefrigerator other than a norcold?
 
Can you convert that icebox by installing a compressor and evaporator like this:

9_Compact_cooling_units__air_cooled_rdax_210x158.jpg


That's what my boat came with. Just this week I removed the rivets that held the "O"-style evaporator together and converted mine to a refrigerator only:

evaporator.jpg


Now, as for a portable, I also have a Dometic/Waeco freezer that I love. It's very efficient at around 4 amps when the compressor is on. They make a number of sizes:

cf_handles.jpg


http://www.dometic.com/enus/Americas/USA/Marine/Refrigerators/Refrigeration/?productdataid=85492

Top load is best as to not let all the cold air out when opened. These are also almost silent when they run.

BTW, you might want to upsize that battery to a 31 if you're going to run a refrigerator for any length of time.
 
That technology ("superconductor cooling technology") is not very efficient and doesn't cool that well. If it did, you wouldn't still see compressor technology used in refrigerators.

Without shorepower on your boat, adding a refrigerator will be a big mistake. That's why your boat came with an icebox.

A small boat refrigerator will draw between 3 and 5 amps of current. At best, that's 72 amp hours over 24 hours, at worst, 120 amp hours. That is more than your battery can supply without being recharged.

I suggest repairing the ice box or finding another one that will fit. The other option is adding shore power and additional batteries. That's a pretty complicated and expensive option.
 
And additional batteries is added complexity in charging and a lot of weight
 
Ron is right about the "superconductor" cooler. They usually claim to cool 40 degrees lower than outside temperature...but that's a stretch. On a hot summer day, they're just not very efficient. I carried one on my old boat and it ran the batteries down in no time.

But adding a fridge may not be out of the question. I removed my ice box, purchased one of those $89 dorm fridges..it fit in the space perfectly...beefed up my batteries, added an inverter plugged it in and it worked like a charm. I didn't have shorepower either but a 50 extention cord with a pigtail adapter was the next best thing.

Something to consider. Good luck.
 
The "dorm fridge" and the inverter to operate it IMO is the way to go. Together they're a lot less expensive than a DC fridge that really works. You WILL need to upgrade your batteries. At the dock, simply unplug from the inverter and plug in to the extension cord.
 
I'll parrot what's already been said on this topic. The electronic superconductor technology leaves a lot to be desired. They really don't even make good carry-along coolers for automotive use. I had one for my car, it "looked nice," like a small fridge. My wife must carry meds with her when we go on a trip, and they must be kept cool. It only lasted a couple months before it began blowing fuses.

I concur with the college dorm fridge and an inverter to power it. Just be sure to get a decent quality inverter, not the cheap $40 job from Harbor Freight (which I have - a 400 Watt model). The one I have has a cooling fan and it makes a good deal of noise when it's running. Then, when it approaches its rated power limitation, the damn thing squeals like an alley cat - very annoying! Pay the extra bucks and get a true sine wave model. You'll be glad you did. Also, get an inverter that is rated for at least 150% of what the fridge's power requirement is. Their output tends to be somewhat "exaggerated" by their manufacturers.
 
Thanks for the feedback folks. Ive decided against it. Ive had one of those 'superconductor' plug in coolers before and its performance was underwhelming at best!
I didnt read between the lines enough and didnt realize that DC fridge was the same technology. I will continue looking for a used Norcold or Dometic. I guess some things you just cant skimp on..lol.
 
quote:
Originally posted by Chriznat20

Thanks for the feedback folks. Ive decided against it. Ive had one of those 'superconductor' plug in coolers before and its performance was underwhelming at best!
I didnt read between the lines enough and didnt realize that DC fridge was the same technology. I will continue looking for a used Norcold or Dometic. I guess some things you just cant skimp on..lol.

Click to expand...

That was a smart move even saying they are underwelmingly poor performers is true. You would be better off with a cooler full of ice.
I have never seen one do much more than keep ice cold soda cans (when they went in) cool not cold.
Bill
 
Perhaps one of the boat boneyards might have one they removed from a total loss might have a nice used unit?
I am very happy with my Norcold DE0081T for 7.1cu feeet with a freezer it draws 2.8amps total current and it doesn't run constantly.
To bad my old unit isn't still around I would have given it to you. I wanted a newer unit my old unit, the original had some slight rust on the bottom of the frig door. It also drew about 4 amps vs. 2.8amps. I really would not suggest going the inverter route it can get pretty complex and expensive plus anytime you convert your in trouble because there are losses involved.
Bill
 
There ARE DC fridges that actually use a compressor... They work well but they're not cheap. The "solid state" or "superconductor" fridges are a joke. Some AC/DC fridges are actually AC fridges with an inverter built in.

A good compressor DC fridge is probably better than an AC fridge on an inverter, but for the difference in price I'm willing to accept the "losses involved". And it's not all that complicated.
 
quote:
Originally posted by stmbtwle

There ARE DC fridges that actually use a compressor... They work well but they're not cheap. The "solid state" or "superconductor" fridges are a joke. Some AC/DC fridges are actually AC fridges with an inverter built in.

A good compressor DC fridge is probably better than an AC fridge on an inverter, but for the difference in price I'm willing to accept the "losses involved". And it's not all that complicated.

Click to expand...

Willie with your large solar array and house bank you or even my boat could stand the extra losses. I'm not sure his boat really has the overall capacity?
Bill
 
My solar array is nothing but a generator, except it does NOT run at night, and I cannot start it up at will. I have to make up those shortcomings with batteries.

Fact is, fridges pull a LOT of power. The difference in efficiency from an inverter is not all that much, maybe 10%, and if he's that close to the edge he needs to upgrade his battery bank. Period.

For what he saves with an inverter and AC fridge, he can buy a couple good batteries. If he can find a good DC "take out" that's great, but he'll still need batteries to run it.

Don't want to carry batteries? Carry ice instead.
 
Willie that is a good perspective on it. However I don't agree in my case if the frig ran a 1/2 hour per hour that would be 1.4AH's or x 24 = 29.6AH's a day removed from the source. I didn't say he might not need another battery but with an inverter he will definately need another battery, source to charge it, marine grade wire, fuses and an inverter.
I agree if you don't want to carry batteries Ice is the next best option.
Bill
 
Chris: Nothing wrong with ice especially if you use a smaller day cooler loaded from the main box for frequently acessed stuff and avoid frequently opening the big box.
 
Ask around at some marine appl. dealer or boatyard for an older used norcold or domestic (in the size you want) that doesn't work. 9 times out of ten the power supply is bad and thier to costly to replace. The compressor on these small units came in two sizes a 40 watt or 60 watt AC. Just supply 110v to the transformer and see if the compressor runs. Most of the time, you can't use the stock thermastat, replace it with a $15.00 fridge thermstat from Grainger. I installed a fridge on the bridge for a cold one. I used a small inverter about a 400 watt unit, the draw is small and the unit doesn't even get warm. I installed a switch (DTDP)to go from 110v (shore power) to the inverter output while underway. I would't leave the unit running all the time, but for the weekend it's fine.
 
You might also try an RV dealer or RV repair shop. They use basically the same Norcolds in RV's.
Bill
 
I shopped around for a small fridge to replace my ancient Norcold. I found one that fit the space perfectly and it has a nice freezer compartment that actually freezes things. I powered it with two Group 31 batteries and an inverter. Unplug the boat from the dock and the transfer switch in the inverter puts the fridge on line. Cruise for 4-5 days without shore power and the fridge works fine. Come home, plug into the dock and the inverter charges the batteries.

The new domestic fridge has much better insulation than the Norcold and the better lip seal around the door makes a difference as to how often the compressor in the fridge cycles.
 
+1 on the dorm fridge route. All told you will be out a bit less in the short run but if the dorm fridge goes bad, you are out 50 -60 bucks to replace.
 
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