Coleman Stirling Power Coolers

[jedwards]

"Why" is because the technology is easily capable of reaching "cryogenic" temperatures and could be used to facilitate advanced sensor and targeting systems. Because of this capability sale of these units falls under the "restricted technologies" blanket of the US Dept of Commerce.
"How" is by ordering something and I will send you a form to sign and fax back to me. After verifying, to the best of my ability, that you are not a North Korean, Lybian, Cuban, ?Brazilian? or Chinese spy, I will send you stuff as soon as payment clears.

[Delezynski]

OK Guys,

Please help out a simple guy here. I am looking to replace our refer unit in our Nor'Sea 27. I built in a Norcold unit more than a few years ago, (story and photos on my web site). I put in some super insulation and it has all been working well. BUT, it is now very old and I think I hear some strange sounds coming out of it. When I first put in the Norcold unit and connected it up, the running draw was a bit under 4 Amps (12 volt). It is now gone up to about 4.5+/-.

As of now, I think I am going to just put in a shelf and mount a portable box. That way, when it goes toes up, I can easily replace it. I MAY get two units, 1 to freeze, 1 to ref.
When I look at the stated power requirement for the Coleman unit, it states about 4 Amps, (40 to 48 Watts). When I look at a similar sized unit by Engel, it draws about 2.3 Amps (27~28 Watts). Also, the Engel unit automatically switches to the 110 Volt when it's connected. I LIKE that feature.

Our boat is small and I do NOT have a lot of real estate to fly solar panels. So, that small difference (1.7 Amp) is a BIG one for me.


Why would I select an item that draws 4 Amps over one that draws 2.3 Amps?


Greg
PS... I am NOT trying to start a food fight here!

[witzgall]

Greg;

To answer your question, the Coleman box draws a max of 48 watts at it's highest setting, which is as a freezer. If you are using it as a refer, it can be drawing as low as 8 watts. I think in real world use, you are looking at 2 amps draw as a nice refer unit, but remember, it is only .9cuft of interior space. Perhaps Jedwards can cofirm or adjust these expectations?

Having said that, since you already have a nice, VIP insulated box, why not go straight for an icebox conversion kit this time around?

Chris

Originally Posted by Delezynski

OK Guys,

Please help out a simple guy here. I am looking to replace our refer unit in our Nor'Sea 27. I built in a Norcold unit more than a few years ago, (story and photos on my web site). I put in some super insulation and it has all been working well. BUT, it is now very old and I think I hear some strange sounds coming out of it. When I first put in the Norcold unit and connected it up, the running draw was a bit under 4 Amps (12 volt). It is now gone up to about 4.5+/-.

As of now, I think I am going to just put in a shelf and mount a portable box. That way, when it goes toes up, I can easily replace it. I MAY get two units, 1 to freeze, 1 to ref.
When I look at the stated power requirement for the Coleman unit, it states about 4 Amps, (40 to 48 Watts). When I look at a similar sized unit by Engel, it draws about 2.3 Amps (27~28 Watts). Also, the Engel unit automatically switches to the 110 Volt when it's connected. I LIKE that feature.

Our boat is small and I do NOT have a lot of real estate to fly solar panels. So, that small difference (1.7 Amp) is a BIG one for me.


Why would I select an item that draws 4 Amps over one that draws 2.3 Amps?


Greg
PS... I am NOT trying to start a food fight here!

[jedwards]

48W for the Coleman unit is worse case scenario. 0 deg F inside and 110+ deg F outside. At more realistic temperatures 40 deg F inside and 90 deg F outside power consumption is around 12W or 1 amp.

If you want to compare the two it is vitally important to recognize that Rankine and Stirling are DIFFERENT animals. The Rankine will consume what it consumes and is controlled by an on/off cycling or Duty Cycle. The FPSC literally turns itself down, very much like a "dimmer" switch, so it only provides enough heat lift to maintain the set point temperature. This means a smaller capacity FPSC unit can provide comparable performance to a larger capacity Rankine and the FPSC will use the least amount of energy possible (as of 4/16/08) to perform the same job. If you were to only look at running draw, the low cost Twinbird FPSC will use about half the energy of a typical compressor sized for the same task. If you add in the surge loads associated with the on/off cycling of the Rankine compressor then the discrepancy grows even faster.

If you want to save money, find a Coleman online or buy through Global Cooling. If you want the minimum power consumption in a portable "Coleman" type unit the the SC-DF25 is it. It uses VIP insulation for the lowest heat leak and can hold below -40 deg C/F if for some reason you wanted it to (maybe you have some awesome fresh fish you want to keep that way for 6 Months ;-)).

[witzgall]

JEdwards;

Funny thing, before I realized that Global had a unit with VIPS installed, I was doing my typcial "what if", and thinking what would it take to surgically scoop out the installation in the Coleman unit and replace with VIPs, cutting from the bottom. And then I realized you already make this!!!
So this begs the question, what might an individual pay for the SC-DF25?

Also, could you comment if this would be a reasonal use of the unit:

When at dock before sailing, or when motoring, cool the box down as far as it would go. With a typical mix of frozen items, I would think this could go a long way in reducing run times once leaving the dock or when the engine is shut off. In essense, running it like a holding plate system.

Comments?

Chris

[Delezynski]

Chris,


I think I may also be reaching the end of life of my VIP panels. Also, it gets to be a big project to put the unit into the box. I am cruising now and don't want to start that big a project as we sail. MUCH easier to just put in a shelf and never have that big a project again.


The specs for the Engel MT17 Power consumption is 0.6 - 2.3 Amps (7.2 Watts to 27.6 Watts). That MAX use of 27.6 Watts is a BIG draw for us!


I think ALL of the units are on only when needed. Our Norcold cycles on and off. So from what I can see, for a given box size and total R factor, the total draw would be less for the Engel unit?


I would LOVE to see some real world data from some one who has one of the Coleman units. There are a lot of cruisers here (in the Sea of Cortez and on the Baja) with Engel and Waeco units. The Engel units seem to be favored.


For our boat, it's ALL about the power used! When we are out, we only have solar, and not a lot of that.


Greg

[clausont]

Greg,

Here are a couple of links to the performance information and tech papers that may be helpful:
Global Cooling - Technology Overview
Global Cooling - Technical Papers

Thanks

[Delezynski]

Originally Posted by jedwards

48W for the Coleman unit is worse case scenario. 0 deg F inside and 110+ deg F outside. At more realistic temperatures 40 deg F inside and 90 deg F outside power consumption is around 12W or 1 amp.

JEdwards,

I can tell you have not been in the Sea of Cortez during the summer. Add to the 100+ deg F air temp that the water is over 95 deg F!

I am interested, but need more info before I decide. The Engel MT17 fits into the space I have and would not require a big project. Remember we are living full time on our Nor'Sea 27 and the wife is not happy when I start a project. And cutting wood is a big No-No.

I thought I saw a unit that would sit on top of our current box (like mounted in the lid) and work. But the specs only called for an inside temp of about 40 deg F.



Our priorities are (in order)


LOW power usage over time.
Easy to install in the space we have.
Cost


Please note, cost is last!

Greg

[jedwards]

It may be best to think in temperature difference. The Coleman unit can consume as much as 48W while maintaining a 110 deg F differential, so... if you want to keep your fridge at 40 deg F inside then the unit will draw 48W only if it is 150 deg F outside. Now, I know that its warm down there but come on, 150 deg F! We have done some comparisons between the various competitors I will try to summarize:



Engel 22 Dometic RC3000 Norcold 415 Kollatron F-86 Coleman Stirling TB SC-DF25 Capacity (Qt) 22 30 15 37 26 26 Max Delta T (°F) 86 30 78 86 104 154 Pulldown from 110°F to 0°F 4 4.5 3.5 3.2 3 1.4 Weight (lbs) 35.3 42 33 53 32.5 32.5 Power req (freeze mode)* (amps) 3.1 6.3 3.5 3.3 3 2.1 Power req (freeze mode)** (amps) 1.7 6.4 1.6 2.5 1.1 0.6 Warranty (year) 1 1 1 1 1 1 Retail ($) $649.00 $699.00 $695.00 $799.00 $599.00 $1,415.00 *Freezer Mode @ SS @ 110°F ** Freezer Mode @ SS @ 72°F

[jedwards]

Whew! that didn't work.

Can somebody tell me how I can post an image of this spread sheet?

[jedwards]

Lets see if this works.

[clausont]

That worked.

[jedwards]

OK.. I think I'm getting a handle on this posting thing...

[cantxsailor]

I have now had my Engel35 for about 2months and love it. It is about the same size physically as a 40qt ice chest but you can get more "stuff" inside because theres no ice. Pretty small for a big boat but perfect for my PSC25.
Engel makes them up to 120qt size, 2 compartment 1side fridge 1side freeze.
Mine runs intermitantly during the heat of the day(no a/c on my little boat) out of the sun under the galley table and will freeze a gallon jug hard as a brick over night. On its lowest setting(ie1 to 5, 1 being fridge and 5 being freeze) mine draws < 1amp with the ambient temp at about 75f on freeze at the same ambient it draws<3amps.

I haven't noticed any extra heat in the cabin. They are all top loading units so you don't have all your cold fall on the floor every time you open the door.

I don't claim to know anything about the design or theory or engineering of the Engel, I do however know they work.

As for longevity, a close friend who is an oil and gas surveyor and spends much of his time out in the back country in a big Ford f350 4x4 bouncing around on farm trails and bush roads has had his Engel in pretty much continuous use now for over 20yrs. His fridge looks like its been down more than 1 flight of stairs and is pretty crusty looking all round but works perfectly. He has the anchor plate so it dosen't bounce around to much but I'd be willing to bet it has taken more punishment in his truck than mine will in my boat.

As has been mentioned elsewhere they are 12vdc and 110vac, can be plugged into both at the same time and will automatically switch to 12vdc if the 110vac is interupted. I personally like that a lot.

My personal experience with "marine" refrigeration has been about the same as my experience with "marine" toilets and outboard engines. They are generally very expensive to purchase(in comparison to land based units) and maintain in both time and money and usually die at the worst possible moment.

This is a personal peeve of mine. I realize the marine environment it a pretty tough place but why can't a small out board work as well as my lawn mower. My mower is 26yo and has never had so much as an oil change. It runs on last years boat gas and is constantly hitting rocks and stumps and various assorted items in the grass that would kill an outboard.
My house fridge is 22yo and despite what my wife may believe is as good at its job as it ever was although probably not as stylish as it once was.
We won't even discuss the toilet.

There now I feel much better, rant over. Hopefully I have helped someone............martin

[jedwards]

After looking at that price sheet (I could barely read it and I wrote it) I am trying again.