Holding plate freezer 12v recommendations

[bobfnbw]

I'm not a expert on refrigeration by far.. Yet... but in my research on this, I have found that the Seafrost DC5000 was the best for my anticipated needs, Except in the cash department. Its expensive. 2 holding plates in a 5-6 cf freezer and 1 in a 6 cf refrigerator should do it. I planned on using either carbon foam or Lifepo4 battery bank and a high output alternator plus ~600 watts of solar to run it. But final purchase will depend on a few things that I won't know till i'm ready so.. Not sure what plates you have. Maybe that is your issue.

[john61ct]

My understanding is that the battery bank is irrelevant for holding plate systems.

The whole point is to "charge" the plates when dino juice is producing high amps, the compressor is not run off the bank.

In effect the "coolth storage" of the bulky and heavy eutectic plates is substituting for the portion of the battery bank that would carry the load for an evaporator system.

If you pay extra for holding plates *and* for the extra bank capacity, you're unnecessarily doubling up on costs and weight, and wasting precious freezer space.

Any feedback on this would be most welcome.

[Typhoon]

Originally Posted by john61ct

My understanding is that the battery bank is irrelevant for holding plate systems.

The whole point is to "charge" the plates when dino juice is producing high amps, the compressor is not run off the bank.

In effect the "coolth storage" of the bulky and heavy eutectic plates is substituting for the portion of the battery bank that would carry the load for an evaporator system.

If you pay extra for holding plates *and* for the extra bank capacity, you're unnecessarily doubling up on costs and weight, and wasting precious freezer space.

Any feedback on this would be most welcome.

You are precisely correct.

You can store the energy in the plates or in your batteries. Also temperature swing in a holding plate system can be as much as much as ten degrees .

I replaced all this with two of my BD35 systems . Freezer was almost 7 cubic feet , after an nondestructive insulation upgrade in that section it worked fine. The old system was horribly noisy, killed the batteries and weighed almost 300lbs

The new system now runs on solar alone .

Regards John

[a64pilot]

Originally Posted by john61ct

My understanding is that the battery bank is irrelevant for holding plate systems.

The whole point is to "charge" the plates when dino juice is producing high amps, the compressor is not run off the bank.

In effect the "coolth storage" of the bulky and heavy eutectic plates is substituting for the portion of the battery bank that would carry the load for an evaporator system.

If you pay extra for holding plates *and* for the extra bank capacity, you're unnecessarily doubling up on costs and weight, and wasting precious freezer space.

Any feedback on this would be most welcome.

Depends,
I don’t want to rely on Dino juice, I want to do it on Solar, so therefore I want or need big Solar, and a big bank gets me through those days when there isn’t enough Solar, back up is run the generator, which cause I’m an AGM bank, I recognize that I will need to burn some Diesel to get to truly 100% SOC regularly for longevity.
I could go with a much smaller bank if I were to accept daily dawn generator runs, but I don’t wish to do that, so I need a larger bank.
Plan is maybe twice weekly generator runs where we make water, wash clothes, make ice and get through bulk and most of absorption in the morning, then allow the rest of the day for Solar to pack in that last 10% or so of charge.

Plus due to increased cycle life expectancy of a bank that is only discharged less than say 25%, I figure the increased cost of a large bank is somewhat off set by its longer life.
Downside is of course weight, but my boat tolerates weight gain better than most, but if I were a high performance lightweight multi, then I could see going much more heavy on a generator, cause fuel has a very high energy density per pound.

[a64pilot]

TJD, you don’t want 404, first cause you don’t need it, you can get what you want with R-134A.
Secondly you will be in a fix come time to get it recharged, cause not everybody has or can get 404, R-134A is the automotive standard, and therefore is very easy to get.

I’d say Oze Pete’s system sounds awful good to me, and I believe it’s air cooled. My preference is air cooled, cause it’s simple, and I like simple stuff.

[john61ct]

Originally Posted by a64pilot

large bank

my point is if you have a big bank lots of solar and multiple charge sources, there is IMO little advantage to paying the premium for holding plates and giving up so much fridge space.

[a64pilot]

I can see that as I don’t really often use my cold plates, by that I don’t often allow them to phase change, I like my freezer colder than that.
However I have 14 cu ft ice box, and a 40 qt Engle.
I can give up some space, and come that day for whatever reason that my fridge is on the fritz, I have about two days to fix it, buy some ice etc. before I start to lose food, likely three days, cause just to look at them, the cold plates look like they hold maybe 5 gls each, and think of having 10 gls of “blue ice” containers in an ice box, how long til they completely melt?

Plus if I start really wanting to be energy conscious, I can turn my fridge off in the afternoon and back on in the morning when the Solar is coming into its own. I have 1000W of Solar, and my break even point when both fridges is on is about 10 amps or about 130 W. It doesn’t usually take long for my panels to make more than 130 W.

The cold plates give me options that I don’t have with just a regular evaporator.

[Colin A]

Originally Posted by a64pilot

TJD, you don’t want 404, first cause you don’t need it, you can get what you want with R-134A.
Secondly you will be in a fix come time to get it recharged, cause not everybody has or can get 404, R-134A is the automotive standard, and therefore is very easy to get.

I’d say Oze Pete’s system sounds awful good to me, and I believe it’s air cooled. My preference is air cooled, cause it’s simple, and I like simple stuff.

Yeah refrigerant is a tricky issue right now. Marine applications are in a gray area between Home HVAC and Auto HVAC. Most stick with 134 because it's less hassle.

134 should work fine. Sounds like you need to source a higher capacity electric compressor. There used to more guys making those for the Marine market but now most have settled on smaller units for lower but longer current draw.

[Dougtiff]

The GB "SPIDER" holding plates were much more efficient than any other plates, too bad you tossed them, as a new system could have been interfaced with them.

[Wind River]

I have bought several used Sea Frost holding plates with two cooling circuits in each of them. I will be running and engine drive system through one circuit and a 12 volt on the other to help maintain the temps between engine runs if needed.

I am not cruising at the moment but keep my boat on a mooring. An engine drive holding plate system, will draw a box temp down much faster than a 12 volt holding plate system and since I am not at my boat all the time I will not leave the system running while I am away. When I do come on board it will need to be brought down to temperature very quickly. While this is not the way you use your system the same principle applies. A lot of cooling in a short time.

I will be building the system myself so I can't point you to provider for this but it sounds like the type of system for you. I got most of my info on the engine driven system from Richard Kollmans book and a few email conversations with Rich Boren (Cool Blue). Granted, this a lot more complex than your old system but has built in redundancy also. Repair the 12 volt side and you are half way there.

It seems that the pro's here believe the R134 is up to the task.

If not, I can send you the address of my dumpster for your old system.

[OzePete]

Originally Posted by ColdEh Marine

You are precisely correct.

You can store the energy in the plates or in your batteries. Also temperature swing in a holding plate system can be as much as much as ten degrees .

I replaced all this with two of my BD35 systems . Freezer was almost 7 cubic feet , after an nondestructive insulation upgrade in that section it worked fine. The old system was horribly noisy, killed the batteries and weighed almost 300lbs

The new system now runs on solar alone .

Regards John

Hi John, did you fit both of those BD35 systems to that 7CF freezer? That is getting closer to the performance the OP required.

Cheers Pete

[Boatguy30]

I think the problem is trying to have a 6 cu ft freezer on one BD50? Compressor. Assuming tropical conditions, even with good insulation it will need to run nearly flat out.

[Badsanta]

Ozepete has a great looking spillover system. I like that it doesn't let the moist air mix with the freezer. Great idea.

[TJ D]

Originally Posted by Dougtiff

The GB "SPIDER" holding plates were much more efficient than any other plates, too bad you tossed them, as a new system could have been interfaced with them.

Yes, too bad indeed. The vendor who sold me the new equipment had a good sales pitch-newer, more efficient, better all around.

If I had it to do over again, I would have put more effort into repairing the GB.
But, that's water under the bridge now.

[a64pilot]

Originally Posted by OzePete

Hi John, did you fit both of those BD35 systems to that 7CF freezer? That is getting closer to the performance the OP required.

Cheers Pete

I think John did it right, but that I mean some really, really good efficient insulation. That from an outside appearance seems to be his trademark, and of course if your insulation is crap, your not going to get an efficient system, no matter how efficient the mechanics are.