Refrigeration kit recommendation

[s/v Jedi]

Originally Posted by newhaul

Actually with my cool blue I never have had issues with fluctuating temperatures. The probe needs to be on the plate . And keep the frost to a minimum.
I charge lfp with solar till mid day or so then run the fridge in the afternoon but with 4 inches of cryogel I do have an extremely efficient box .
Had the same system on the spencer that renegade owns now . Never had any issues on her after installing the solar and new batteries the ones that came with the boat were worn out .

The food stored doesn’t care about plate temperature, it cares about box temperature. Actual installations with holding plates have larger box temperature swings than evaporator systems (not enough plate surface area compared to evaporator surface area) and this reduces food preservation span.

Also, a plate system is designed to be charged by an unlimited energy source, like a compressor mounted to a diesel engine, then use no energy at all. The process to freeze the plate is not energy efficient but that was not the design goal. When you have DC energy available from solar, running a small compressor on low rpm’s continuously is far more efficient than brute force freezing a plate. The plate always looses compared to evaporator and that was even before LFP batteries came along improving efficiency.

For a system with a holding plate, LFP batteries are irrelevant because they should not be used. The plate should bridge the dark hours, not a battery.

[kenbo]

For a 5 cubic foot cold box, I believe the OP would be served well with an evaporator based system with an air cooled BD35 compressor. Nova Kool makes a very reliable, simple system that is priced very fairly.

But any new system requires fine tuning to maximize the value of the Secop variable speed compressor. Adjust the resistance between the thermostat and ECM to get the compressor to a 50% duty cycle.

[Mongo_at_sea]

Thanks Kenbo for the recommendation. I tend to the evaporator type as I have plenty of battery capacity, and use solar not the engine to charge it.

[newhaul]

Originally Posted by s/v Jedi

The food stored doesn’t care about plate temperature, it cares about box temperature. Actual installations with holding plates have larger box temperature swings than evaporator systems (not enough plate surface area compared to evaporator surface area) and this reduces food preservation span.

Also, a plate system is designed to be charged by an unlimited energy source, like a compressor mounted to a diesel engine, then use no energy at all. The process to freeze the plate is not energy efficient but that was not the design goal. When you have DC energy available from solar, running a small compressor on low rpm’s continuously is far more efficient than brute force freezing a plate. The plate always looses compared to evaporator and that was even before LFP batteries came along improving efficiency.

For a system with a holding plate, LFP batteries are irrelevant because they should not be used. The plate should bridge the dark hours, not a battery.

My plate is actually larger surface area than an evaporator based system.
And it's a standard technautics size. I don't get wild temperature swings such as you think . Also having the sensor on the plate is correct for a holding plate system as the temperature of the plate is what regulates the box temperature.
Also the technautics system is actually designed to run off of solar alone .
We usually agree on things but this is one where we will agree to disagree.
Stock holding plate has approx 768 sq inches of cooling surface area .
24"x13"x2.5" stock plate .

Lastly defrosting is easy as the plate is stainless steel so a putty knife or ice scraper makes short work of it as upposed to the thin aluminum of the evaporator system

[s/v Jedi]

Originally Posted by newhaul

My plate is actually larger surface area than an evaporator based system.
And it's a standard technautics size. I don't get wild temperature swings such as you think . Also having the sensor on the plate is correct for a holding plate system as the temperature of the plate is what regulates the box temperature.
Also the technautics system is actually designed to run off of solar alone .
We usually agree on things but this is one where we will agree to disagree.
Stock holding plate has approx 768 sq inches of cooling surface area .
24"x13"x2.5" stock plate .

Lastly defrosting is easy as the plate is stainless steel so a putty knife or ice scraper makes short work of it as upposed to the thin aluminum of the evaporator system

Your plate may well be big enough, but it isn’t the norm. I would suggest you measure box temperature over 24 hours of use and see what the max & min are

[Renegde_Sailor]

Originally Posted by s/v Jedi

The food stored doesn’t care about plate temperature, it cares about box temperature. Actual installations with holding plates have larger box temperature swings than evaporator systems (not enough plate surface area compared to evaporator surface area) and this reduces food preservation span.

Also, a plate system is designed to be charged by an unlimited energy source, like a compressor mounted to a diesel engine, then use no energy at all. The process to freeze the plate is not energy efficient but that was not the design goal. When you have DC energy available from solar, running a small compressor on low rpm’s continuously is far more efficient than brute force freezing a plate. The plate always looses compared to evaporator and that was even before LFP batteries came along improving efficiency.

For a system with a holding plate, LFP batteries are irrelevant because they should not be used. The plate should bridge the dark hours, not a battery.

On my cool Blue I have a 5" computer fan in the REFER side, and have a temp probe in each where the food is stored, not on the plate it's self.

The computer fan is controlled by the REFER temp probe, the Plate by the freezer side.

With the two 100W windy nation panels on the boat, that are linked side to side in a less than efficient manner, meaning if one side gets shaded it drags the other down, even with that setup it will keep the fridge cold indefinitely.

The unit draws far less power than my computer system.

One of my next projects will be rebuilding the fridge box with better insulation, and removing the chart table drawer to extend the height of the box, in doing so I am going to gain a substantial amount of space, and quite a bit more efficacy.



Been running this system since 2016 when I bought the boat, and after I fixed the couple of issues with the wiring, it's been pretty flawless.

Biggest chore is defrosting it about twice a year.

[Bowdrie]

I don't know if Cool Blue/Technautics are still using the same eutectic plate, but the original design plate was absolutely the best plate around, nothing else by any other company even comes close.
It is/was so far in first place that there is no second place, only third or worse.
There is no debate, it is so.

[newhaul]

Originally Posted by Bowdrie

I don't know if Cool Blue/Technautics are still using the same eutectic plate, but the original design plate was absolutely the best plate around, nothing else by any other company even comes close.
It is/was so far in first place that there is no second place, only third or worse.
There is no debate, it is so.

Still the same plate configuration basicly with a transmission cooler inside the plate to freeze things fast.
Something like this is was told .

[Bowdrie]

Originally Posted by newhaul

Still the same plate configuration basicly with a transmission cooler inside the plate to freeze things fast.
Something like this is was told .

While it is similar to the pic you show, the Cool Blue/Technautics fin-tube package is a proprietary item, it has far more tube passes in it than any "transmission cooler" and has specific dimensions to take advantage of the plate size.
It exhibits superior heat transfer ability vs plate size/volume.

[newhaul]

Originally Posted by Bowdrie

While it is similar to the pic you show, the Cool Blue/Technautics fin-tube package is a proprietary item, it has far more tube passes in it than any "transmission cooler" and has specific dimensions to take advantage of the plate size.
It exhibits superior heat transfer ability vs plate size/volume.

I know that but as I said similar to .
Dug up the old manual and here is what it looks like

[s/v Jedi]

Many years ago it was Glacier Bay who was the Rolls Royce of refrigeration and their holding plates with SpiderCoil was legendary and named the best.

Jedi came with that and because of it’s reputation I could sell it for almost enough to buy our new systems.

Here is a good article describing how the shift from holding plate to constant cycling came to be, from an expert

https://www.coastalclimatecontrol.co...Part%20Two.PDF

[AKA-None]

Originally Posted by Uncle Bob

Hey, I'm pretty sure mixing a 10% solution would be difficult for some here.

Is that metric?

[Uncle Bob]

Originally Posted by AKA-None

Is that metric?

But of course, kilograms are so much more betterer than miles.

[Boatguy30]

Nova Kool

[michaeld]

We have had good reliability with our Frigoboat system. The only service required has been replacing the "computer fan" attached to the compressor until.