Anyone have this drawer fridge?

[jaysweet]

I'm toying with the idea of putting one of these drawer refrigerators underneath our stove, where the (useless) microwave now is. The thought is that it would be good for drinks, coffee cream, yogurt for overnights, while still leaving the much less frequently opened icebox for longer trips (with ice, still). It claims to use 3.75 amps, which isn't bad at all if I use it for maybe 12 hours during the day, with solar on, and maybe turn off at night.

Dometic CD-30 CoolMatic Drawer Refrigerator - 1.0 cu ft

 

[jssailem]

Jay. Looks like it could be convenient and fill a specific purpose.
The location under the stove.
Would this conflict with the stove, if it is gimbaled?
With the stove cooking, will this conflict with the cooling of your drawer?
These are things only you can evaluate.

 

[jaysweet]

Jay. Looks like it could be convenient and fill a specific purpose.
The location under the stove.
Would this conflict with the stove, if it is gimbaled?
With the stove cooking, will this conflict with the cooling of your drawer?
These are things only you can evaluate.

John,
The stove isn't gimbaled: it's just a 2-burner fixed propane stove, which would in no way heat up the space below it. Under that, there's the useless (to us) microwave, somehow fixed in a cutout hole. (Probably need to lift the stove up to get at whatever's holding the microwave in.) Under the microwave is a small cabinet that's currently holding pots and pans.

It looks to me like I'd only have to make the microwave opening a touch larger, and then could use the same shelf for the fridge. There's a concern about the depth: I think it's fine for the body of the fridge, but probably not for the compressor. The compressor bolts on the back, though, and is designed to be relocated as needed, with a 1.5 meter long coiled coolant line. So the plan would be to relocate the compressor into the pot/pan cabinet, probably with a grate added in place of the door to allow cooling air for the heat exchanger. A fan and the heat exchanger are integral to the compressor. I suspect the devil is in the details, so I should dig into the space and get the microwave out first to see if it's feasible. Plenty of reviews of this fridge installed in vans and RVs, but not much about it being used in a boat.

 

[jssailem]

the devil is in the details

Absolutely.
You plan sounds solid.
Getting the microwave out of the space will let you work out the combination. Having air movement around the compressor is critical. Opening or slotting the front of the drawer, shortening the drawer to add space in the back, installing a grate all will work to help dissipate the heat.

 

[jaysweet]

So this project is moving forward. I bought the fridge despite some conflicting reports on how deep it is, after making a mock-up of the main body with cardboard and trial-fitting it into the space. The install isn't done yet, but I'm certain now that it will fit: pictures in a bit.

Quick question, though: can I trial run the fridge here in the house (it's a 12V only) by using a small battery charger as a power source? Any risk in doing this? Thanks.

 

[stickinthemud57]

So this project is moving forward. I bought the fridge despite some conflicting reports on how deep it is, after making a mock-up of the main body with cardboard and trial-fitting it into the space. The install isn't done yet, but I'm certain now that it will fit: pictures in a bit.

Quick question, though: can I trial run the fridge here in the house (it's a 12V only) by using a small battery charger as a power source? Any risk in doing this? Thanks.

If you can test it with the equipment you intend to use it with that would be better. Otherwise, just make sure that your battery charger produces adequate amperage.

 

[berner73]

Quick question, though: can I trial run the fridge here in the house (it's a 12V only) by using a small battery charger as a power source? Any risk in doing this? Thanks.

Interesting project and curious how it works out as it's an unique solution for smaller boats. Bench testing is a great idea. Prior to doing so I suggest you reference the manual at Dometic's website where the power requirements are clearly defined, as is the warranty coverage. Relative to the later, I'd be hesitant to use a battery charger unless it's very customizable and you are familiar with how to set output voltage/amps with your particular charger (with proper fusing configured for testing). For situations like this my preference is to use a DC power supply. If you don't have one yet, you may be surprised how versatile they are and how much you will use it once it's in your shop. Best of luck and please update the thread as the project progresses.

Dometic CD 30

Example power supply (less expensive units are available)

 

[jaysweet]

Thanks for the comments: I haven't gotten around to bench-testing the fridge yet, but it'll happen. Here's what the actual device looks like.
It will apparently hold quite a few beers, if one is partial to that sort of thing. And as I mentioned, the compressor on the back is designed to be relocated.



As you can see, it's mounted on a metal bracket, which is designed to be unbolted and moved to bolt on to either side of the fridge, or somewhere else. For my boat, I'll have to ditch the metal bracket and move just the compressor and heat exchanger (which are much smaller) to a shelf I install.

 

[jaysweet]

Here's the place it's going: I've removed the 2-burner propane range top. Below that is the hole where the microwave used to be, filled by a mockup of the fridge body (exclusive of the compressor), and beneath that is a drawer for pots and pans. To the left is the door to the aft cabin. To the right is the ice box (partially visible) and sink.

Here's the existing shelf that Hunter supplied for the microwave:

You can see the curved hull at the back of the space, and the propane hose (which I'll have to lengthen by a foot or two). The next picture is the fridge body mockup, showing that there's really no room for the compressor back there.

So here's the side view:

It's not particularly to scale, but the compressor requires 6" of depth (side-to-side in the drawing) and 6.5 of height. So it's close. Here's a mockup of the compressor (plus heat exch. plus some slop) in the space:

So anyway, even though it's close, I'm pretty confident this will work now.

And yes: I have considered ventilation of the space. More later.

 

[smokey73]

For the bench test. How about hooking up to a 12 volt battery and then the battery charger to the battery. Battery will act as a "buffer" for the charger and simulate its behavior as installed. You can hook a clamp on ammeter on the positive cable and check current draw etc. If you don't want to do more than a "short check" to see if it works, just leave the battery in the car. For that matter, you could probably just run the car and let the alternator do the charging. If you want a longer more realistic test, remove the battery from the car and use the charger. Just my 2 cents

 

[jaysweet]

For the bench test. How about hooking up to a 12 volt battery and then the battery charger to the battery. Battery will act as a "buffer" for the charger and simulate its behavior as installed. You can hook a clamp on ammeter on the positive cable and check current draw etc. If you don't want to do more than a "short check" to see if it works, just leave the battery in the car. For that matter, you could probably just run the car and let the alternator do the charging. If you want a longer more realistic test, remove the battery from the car and use the charger. Just my 2 cents

That's a good idea, thanks. It had occurred to me, although I don't have a battery handy (not counting the car). Back in real life, having felt a little gun shy about doing the easy thing (hooking up the charger directly), I ended up just physically installing the fridge today. So the first test will be when I get it wired up. All or nothing, I guess.

 

[jaysweet]

Here's the compressor, untethered from the big metal shelf. So it's smaller now, but it needed to be bolted to a 1/2" plywood platform to keep the compressor and heat exchanger together in one piece.

The fridge, partially slid into the hole in the cabinet face so I can twist the compressor around, working through the hole where the range will be. This was the hardest part of the whole thing: trying not to stress or collapse the copper tubing, working in a very confined space. It worked (unless I buggered it up and haven't realized it yet), but it was pretty dicey. In the second picture, you can see the shelf I built to mount the compressor above and behind the fridge box.

Here's the "final" placement, with the compressor up on the shelf and the fridge box slid back almost touching the shelf. The extra coiled tubing had to go somewhere, so it went wherever it ended up, pretty much.

A couple of close-ups: LHS of the shelf needed a notch cut to clear the tube coming from the fridge box. RHS, you can see where I secured the smaller platform to the fixed shelf with stainless machine screws with wing nuts underneath.

 

[jaysweet]

Here's the not-quite-final result:

It still needs to be wired up to 12V power. I plan to add a couple of small (very quiet) 12V computer fans to the cabinet face above the fridge. These should pull air from the lower pot/pan cabinet (there are already slots in the horizontal dividers), up the back of the fridge to the heat exchanger, and across the top of the fridge to the fans and out.Probably some wood trim around the face of the drawer would be nice.

 

[Captain Larry-DH]

Your next project- solar power or small gen to feed the power beast. Maybe a battery upgrade

 

[jaysweet]

Did the batteries in May. Solar is next.

 

[garymalmgren]

Great job, Jay.
RE; . I plan to add a couple of small (very quiet) 12V computer fans to the cabinet face above the fridge.

The only foreseeable problem that I can foresee is the amount of heat build around the condenser and compressor.
You will surely need fans to move enough air over them in summer with a fully loaded fridge.
When sizing your air inlet and outlet (in bottom out top,) don't be a miser. the area of both of these should be little larger than the area of the fan orifices.
One other idea would a push fan at the bottom and a pull fan at the top.
Measure the diameter of the fan blades, Get your area and make sure your inlet an outlet are not smaller than that area.
Neat looking slots are much less efficient (turbulence) than a nice big hole.

You moved really fast on this and it looks like a really good project to me.
Must admit that I was a little surprised at the cost of the unit. But the cold beer will be worth it.

gary

 

[jaysweet]

Great job, Jay.
RE; . I plan to add a couple of small (very quiet) 12V computer fans to the cabinet face above the fridge.

The only foreseeable problem that I can foresee is the amount of heat build around the condenser and compressor.
[omitted]
Must admit that I was a little surprised at the cost of the unit. But the cold beer will be worth it.

gary

Thanks, Gary. Yeah, airflow is a concern. On the one hand, I can’t vent the heat exch. in a really direct way, b/c it’s really tucked back up in there. But there are a few positives. First, there’s a pretty large air space around and in front of the heat exchanger. So the fan that’s built into the unit will mix that air around and hopefully get it ready for extraction. The other plus is that Hunter already built the cabinet for ventilation. There are two horizontal partitions. The bottom one forms the roof of the pot/pan cubby. It’s full length (port to starboard) and is tabbed into the hull. But it has a bunch of wide slots cut into it already for airflow. The other one is the shelf for the microwave/fridge, maybe 3-4” above. It also has slots, but with the fridge sitting on the shelf, most of the air will be directed around the back of the fridge where it’s needed, to the heat exchanger. The hope is that the fans can pull all that warm air across the top of the fridge and around the stovetop and out.

As to the cost, it was “only” $757, plus another $100 for tax and shipping, not the $1420 it says on the link someone posted above. The advertised prices are all over the map, but in reality, almost everyone was out of stock. Defender had it in stock and got it to me in 2 days, although it was $150 more than the lowest (unavailable) price. Nothing is cheap with a boat…

 

[berner73]

Wow, you're making great progress. Looks very god so far. Curious to see the final installation and any metrics around real world cooling times (from ambient) and associated power consumption. I could envision using this setup for weekend trips to the boat.

Nice job.

 

[jaysweet]

Wow, you're making great progress. Looks very god so far. Curious to see the final installation and any metrics around real world cooling times (from ambient) and associated power consumption. I could envision using this setup for weekend trips to the boat.

Nice job.

Thanks, Berner. I'm not comfortable accepting congratulations until the thing actually works (after hooking up the 12V power), but I'm 80% confident that it will. Maybe 85%. From what I've read, the power consumption is way lower than the 3.75 amps they claim, but we'll see. If I were less unjustifiably-self-confident, I would have gone for the CD-20, which is exactly the same fridge, but 2/3 the volume (and depth). It would have been a breeze to slide it in place, with no need to relocate the compressor. But I was greedy for the extra 50% volume boost. Only time will tell whether I screwed it up or not.

 

[berner73]

Any updates on your progress? Looking to add some project for the off season and wondering if this should be on the list.

Thanks!