Who provides the best 12 volt refrigeration systems?

[OzePete]

Originally Posted by a64pilot

I can tell you from my experience that if you have some excess cooling capacity, everybody is happy, temps recover quickly when you add in a large heat load like a lot of warm food to Cool or freeze etc.
If you have little excess capacity it takes all day long for the fridge to recover from having a large watermelon placed in it, and you learn to not put the watermelon in and a case of beer or Cola, large container of ice tea whatever.
Secondly, nothing ever seems to work as well as the numbers say it should, and the calculated results are only as good as the inputted data of which there are unknowns, like insulation.

If you check the estimates I posted for this project it shows that even in a worse case scenario based on known factors, the system quoted only requires a 40% duty cycle to provide the freezer's requirements at the Bahamas, so plenty of room for unexpected contingencies like insulation not 100%, adding product or allowing spillover into the adjacent cabinet etc.

Also, this estimator is a product I engineered specifically for marine refrigeration computations and a check will show that it includes for pasting in the ambient variations and most other relevant factors. (In this case 37C) This method of heat load calculation etc is the industry norm, used by myself and other refrigeration engineers for decades, an industry which relies on facts not opinion, prejudice or puffery!

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[john61ct]

Originally Posted by hzcruiser

Here in this thread on CF? I must've missed them.

The two concerned have a long history of sniping at each other, were recently sanctioned for it, so now they keep it "under the table".

Less disruptive but still annoying and damaging to their credibility.

[a64pilot]

Pete, I wasn’t speaking at all to your estimate, I didn’t even look at it.
All I was saying is that this isn’t something that you can always apply a finite engineering analysis to and come up with good results.
Often times in things like this experience is important too, and if your going to error, error conservatively.
Reason is there are too many variables and too many unknowns. R value and usage patterns are large portions of the equation and can only be guessed at, then many boxes are adjacent to the engine compartment, and when motoring pick up quite a lot of heat that way, some are not near the engine compt.

All I was saying is if you don’t go with the idea of finding the smallest system that will work, and instead ensure that the system you get is more than large enough, it’s likely you will be happier, cause you’ll have enough reserve so that the box maintains set temp when motoring, or it’s an unbelievably hot day and that side of the hull is the one in the sun, or you decide or make ice, etc, etc.

However many, many people go with something smaller than what would work well, and often the reason is price, sometimes for just a little more money, they would have a system that maintains set temp better

[Pete7]

Without wishing to drift the thread, can I ask why not put a water cooled fridge widget in a water tank">fresh water tank?

Pete

[Richard Kollmann]

Originally Posted by john61ct

The two concerned have a long history of sniping at each other, were recently sanctioned for it, so now they keep it "under the table".

Less disruptive but still annoying and damaging to their credibility.

john, I agree bad information is dangerous to boaters who might follow it. It is true my analysis is generally different because I no longer wish to sell anything.
The debate on this thread deals with a formulas of matching actual climate conditions to power consumption for a typical blue water boat. My formula allows boat owner to fill in the needed blanks. It is also true not every boater is looking for refrigerator temperatures equivalent to a home refrigerator which my recommendation suggests.

Large numbers of boaters have used this 12 year formula as posted on my web site without complaints. Check it out for yourself. Kollmann Marine

[Mike OReilly]

Once again, I just want to thank everyone who has responded here. As someone just beginning his learning curve on this subject, I truly appreciate all the advice. And I'm sorry my query (re)ignited a squabble.

As any cruiser knows, there is no One Right Answer for any issue. Especially with complex systems like refrigeration, each situation will be special, if not completely unique.

I'll be studying all the information provided here, as I'm sure everyone else will who reads this thread in need. And I'm sure I'll have more questions as I start to discover my unknown-unknowns. [emoji6]

[Bangorang]

2 votes for CoolBlue.
We have one fridge and one freezer that we’re both easy to install and have run flawlessly and continuously throughout a 6 yr Pacific circuit cruise. CoolBlue customer service was great for purchase and installation advice, but never needed them after that.

[a64pilot]

The Cool Blue is an extremely simple system. You literally only connect two sets of wires to it, one set is the mechanical thermostat, and the second set is power.
The only electronics is the compressor controller, which is mounted so that the condenser fan blows onto it to cool it, fan also blows across the compressor. Neither is required, but that extra cooling surely extends the life of the components.

It is as simple a system as I can see that is possible to put together.
I like simple, it’s easier to trouble shoot and fix.

I believe being simple has something to do with them being pretty trouble free.

[Mike OReilly]

Thanks. I am looking for simple, both to install and to maintain. The nova kool systems look easy to install. The come pre-charged with some sort of quick connectors. Is this standard?

[JMitchell]

Originally Posted by a64pilot

The Chinese manufacture a tremendous number of off brand compressors........

Just want to clarify on this. MOST things now days are manufactured in China. Thats not automatically bad, You get what you pay for. Companies that pay for high quality components with stringent QC get excellent quality and durable items. The same manufacturing plant will also built identical copies under a different name with cheaper parts and little QC. You may get a good one, you may get crap.

Generally, you get what you pay for.

[Laureat]

I first bought in 1996 for my Beneteau 430 Oceanis 1987 , a cool blue system, I had to change it in 2006, very good help from Richard, and once again in 2014, because the cold plate in the ice box had not been change since 18 years, and damage my new unit, so Richard sent me another unit with no cost.
What a great fridge system.

[Richard Kollmann]

Originally Posted by Mike OReilly

Thanks. I am looking for simple, both to install and to maintain. The nova kool systems look easy to install. The come pre-charged with some sort of quick connectors. Is this standard?

Most all Icebox conversion refrigeration systems are sold as pre-charged with refrigerant.This type unit is delivered in two boxes condensing unit in one box and the evaporator size you selected in another box. Once the two major units are installed there are two refrigerant lines to be connected. Each manufacturer will have different pre-charge line connectors preventing loss of refrigerant as lines are connected. Because there are at least six different line connectors it is not possible to purchase compressor/condensing unit from one company and evaporator from another company. The best refrigerant line connectors use a final metal to metal final never leak seal. O ring seals under tight compression do not usually leak. Frigoboat and E Z Kold final o Ring seals are not permanent line connector seals.

Yes The Danfoss engineering design BD compressor are built in China but the parent company is still German. As far as I know from reviewing all small direct current compressors under one thousand Btu they all are manufactures in China.

[goho]

i would recomend Engel units, thhey have drop in and portable units. they use vaccum plates which are very efficient. we have two, one smaller which we use as a freezer [minus 10 F.] and their largest which i dropped into the hole where the original benniteau unit had been. they work on 12 volt or 110. great units and no need to call for tech support because they just keep working properly. we have had them for over 5 years and reccomended them to many other cruisers.

[a64pilot]

Originally Posted by Mike OReilly

Thanks. I am looking for simple, both to install and to maintain. The nova kool systems look easy to install. The come pre-charged with some sort of quick connectors. Is this standard?

Yes, it’s standard, but as Richard pointed out as with everything, not all connectors are created equal.
Also a thin plate evaporator is often a critical orifice, which means that getting the correct amount of refrigerant level is very important, and pretty darn difficult to get just right, and it has to be just right, and I mean to less than an ounce.
TXV systems often have a decent sized drier installed, and the drier can act as an accumulator of sorts and hold some excess refrigerant, so charge isn’t nearly as critical or as hard to achieve as a critical orifice system, a little extra doesn’t hurt and gives a buffer if you do happen to have a tiny leak.
I probably shouldn’t post this, have some others confirm or deny please, but the Cool Blue in particular can be bled down to just a little refrigerant pressure is left, a vapor charge if you will, then a complete can of refrigerant added and it’s right at the correct amount of refrigerant, no gauges, no sensitive scales weighing charge, watching frost lines adding in 2 sec shots of refrigerant etc. All you need to carry with you is a can of refrigerant and a service hose, which you can buy at any Walmart etc anyway so depending on where you travel, you don’t even need to carry that.

I should bring up though if you buy an extra can, read the label carefully to ensure its nothing but R-134a, cause for some reason it’s getting tough to find just refrigerant without dyes, leak sealers, and other gases blended in. Maybe go to an HVAC supply store to get a can.

[Caliber40]

Coolblue from Cruise RO.....Rich Boren answers the phone day or night!