Coleman Stirling Power Coolers

[Cowboy Sailer]

Coleman Stirling Power Coolers

Stirling cycle refrigeration has the potential to be the most efficient way to remove heat from an enclosed space as in a refrigerator or freezer. Of course the resistance to heat flow thru the walls of the refrigerated space is very important. Small portable coolers tend to have rather thin walls. This means that the amount of heat that must be continuously removed can be rather high. So the poorly insulated walls can negate the thermodynamic efficiency of the Stirling free piston heat pump that is used to provide the refrigeration in this unit.

Has anyone used the Coleman Stirling Power Coolers as their boat refrigerator or freezer? If so what was your power consumption and what do you think of the unit?
Would it be possible to easily add insulation to the outside of the unit?
Would it be practical to remove the internal mechanical parts and use them in a well-insulated box?

[scotte]

I believe these are made by Waeco. I've heard (but don't know for fact) that they only work when kept quite level, so that may preclude their use on a boat.

Engel coolers are another option - very efficient, but not cheap!

[Cowboy Sailer]

Actually, I think that all of the Waeco coolers use the compressor-condenser-evaporator type refrigeration cycle. I think that they use Danfoss compressors. The Stirling cycle is very different. A company called Global Cooling probably makes the actual mechanical cooling unit for Coleman. Global Cooling has a good Website at http://www.globalcooling.nl/
I was surprised to read that Coleman recommended that their unit be within 12 degrees of level. I don’t know why.
The Coleman unit is speced at 48 watts or 4 amps at 12 Vdc. It is capable of freezing temperatures but with what looks like about 3/4 inch of insulation the heat flow into the cabinet must be very great. To be competitive on a boat a fixed cabinet needs a lot more insulation than that. I am wondering if there is any way to use the Stirling cycle mechanics in a well insulated cabinet.

[RonRicco]

Tropikool has been making a marine version for a while.

TropiKool

Brian

[shipofools]

I have an engel 35 and love it. The power requirements are minimal for the returns, and the product is solid an worry free. Highly recommend.

I went with the 35 vs a larger unit because it fits under my cockpit on a Corsair 31.

[allied35]

I had a Coleman Stirling power cooler on my boat and I loved it!!!!!!!
I had one 75w solar panel and 2 house batteries that would barely hold a charge and that was enough to run the cooler on it's coldest refrigerator setting (it has 2 more "freezer" settings). Coleman claims it uses 4 amps but I think that is only when it is on its coldest setting and the unit is out in the sun. I think the way I used it, on the coldest non-freezing setting and inside the boat where its cooler, it used only about 1 or 2 amps.
The cheapest place by far to buy one is at Costco online. I paid $390 there when Coleman's website wanted nearly double that.
You would have to be mentally retarded to buy a "marine" refrigeration unit after seeing one of these beauties. This technology makes compressors, cold-plates, refrigerant etc obsolete. Why spend thousands on some overpriced "marine" piece of crap that you know won't last more than a year or 2 before needing expensive repairs when you can buy one of these, plug it in and you're done for less than $400!
Plus the Coleman unit has no wearing parts and no freon to leak out.
I "installed" mine by cutting a hole in the bulkhead between the sail locker and the old ice-box and sliding the Stirling cooler in. That way when I'm in the galley, I just lift the lid of the ice-box, then open the top of the Stirling cooler and there's my cold beer! The controls can be reached from the top, it's a bit awkward but it's not like you need to use them often.
Buy one and tell all your cruising friends too.
I sold my boat in August but will definitely have one on my next boat too!

[GordMay]

Originally Posted by allied35

... You would have to be mentally retarded to buy a "marine" refrigeration unit after seeing one of these beauties. This technology makes compressors, cold-plates, refrigerant etc obsolete. Why spend thousands on some overpriced "marine" piece of crap that you know won't last more than a year or 2 before needing expensive repairs when you can buy one of these, plug it in and you're done for less than $400! ...

My $500 - $600 Adler-Barbour refer' cooled (8.5 cu. ft.) about 10 times the volume of this $400 Coleman (0.8 Cu. Ft.), and was running trouble-free (and service/repair free) after 10 years of live-aboard use.

On behalf the of all (if any others) the retards amongst us, let me say that we're pleased that you're pleased with you refrigeration choice.
We're much less pleased with your disrespectful characterization of those with differing opinions, making different choices.

[Alan Wheeler]

Plus the Coleman unit has no wearing parts and no freon to leak out.

And honestly, I am not picking on you, but this statement is simply not correct. A Stirlign engine does have moving parts and sadly the one major issue with them is that they wear out rather quickly when compared to a regular lubricated engine.

[David M]

Could someone have mistaken a Sterling engine with a Peltier cooler?, which has no moving parts.

Thermoelectric cooling - Wikipedia, the free encyclopedia

Peltier (TEC) Cooling - Tom's Wiki

Stirling engine - Wikipedia, the free encyclopedia

[Alan Wheeler]

I was wondering that?
But if it is the solid state device, unless major advancements in those Pletier devices have occured, they are extrmemely inefficient. We had one and the current drain over night was huge. About three times the amount our 12V compressor unit draws that replaced it. Plus the new unit cools more volume.

[Cowboy Sailer]

My dear Mr. Alan Wheeler,

The usual implementation of the Stirling Cycle as an engine does indeed have moving parts that wear against each other and require lubrication to minimize friction losses and wear. The mechanism used in the Coleman Stirling cycle is a free piston that floats the moving piston on what would be called “air bearings” except that the working fluid is Helium so I guess that they are more properly described as “Helium bearings”. This really, really lowers contact wear and friction.
This method of cooling is very different from Peltier effect cooling. The Peltier effect can only provide about 40 degrees of cooling per p-n junction pair. To get very cold temperatures one must stage them so that the heat pumped to one end of the junction is removed by a much larger next stage. Three stages are about the limit of practical use. I used a small three stage Peltier cooler to cool an infra-red detector in some space and aircraft equipment that I designed once. But I digress.
The Tropikool unit used a thermo siphon using carbon dioxide as the transfer fluid. I don’t know if the Coleman unit also uses a thermo siphon technique to transfer the heat from the cabinet to the cold end of the Stirling apparatus. If so, that may explain why they said that it had to be within 12 degrees of level.
I really appreciate allied35 telling about his experience with a Coleman Power Cooler. I also am glad that shipofools told about his Engel 35. I remember that an earlier post about refrigeration where someone ripped the guts out of an old rusted portable Engle cooler and re-installed the works in a well insulated built in compartment on his boat. That got me to thinking, “If one could use the more efficient Stirling cycle and have a very well insulated box, wow, a low energy deep freeze!” The Stirling cycle stays very efficient at sub zero temperatures unlike the Rankin cycle which looses efficiency at deep freezing temperatures in the tropics.

[allied35]

Originally Posted by Alan Wheeler

And honestly, I am not picking on you, but this statement is simply not correct. A Stirlign engine does have moving parts and sadly the one major issue with them is that they wear out rather quickly when compared to a regular lubricated engine.

No, you are not picking on me. The Coleman Stirling powered Cooler is not powered by a Stirling engine. It uses the Stirling principle to move heat. It does this by using a magnetized piston that is moved back and forth at high speed by electromagnets. This piston rides on gas bearings and therefore it has no wearing parts. I did not say that it has no moving parts. It does not use freon either.
Also the "one major isssue" with sterling engines is not that they "wear out rather quickly when compared to a regular lubricated engine". That is absolute nonsense. Stirling engines are lubricated just like regular engines. The reason Stirling engines never became popular is that they cannot, without a lot of added complexity, be throttled quickly. Therefore they are not suitable for use in vehicles. They are not very competitive in stationary applications either due to their higher costs.

[Cowboy Sailer]

I found the original post that I referred to in my earlier post. It was Bob Norson on 19-06-2006 in a thread called Engel Refer Unit. It was, of course, in Engineering & Systems> Plumbing:Water,Waste,HVAC & Refrigeration

[allied35]

Originally Posted by GordMay

My $500 - $600 Adler-Barbour refer' cooled (8.5 cu. ft.) about 10 times the volume of this $400 Coleman (0.8 Cu. Ft.), and was running trouble-free (and service/repair free) after 10 years of live-aboard use.

On behalf the of all (if any others) the retards amongst us, let me say that we're pleased that you're pleased with you refrigeration choice.
We're much less pleased with your disrespectful characterization of those with differing opinions, making different choices.

Oh, don't be offended, The Coleman unit wasn't around ten years ago when you purchased your Alder Barbour.

[GordMay]

At less than a 1 Cu. Ft. Storage capacity, the Coleman Stirling Cooler may be a suitable portable travel accessory; but wouldn’t be large enough to satisfy most cruiser’s refrigeration needs.
Does anyone know of a commercially available Stirling Refrigerator, preferably a drop in (to existing box) type unit.
To be practicable, the unit should be capable of refrigerating at least 4-5 Cu. Ft., preferably over 8 Cu./ Ft.