using open small fridge to cool small insulated closet?

I have a small crawlspace closet under my stairs which is from 2 feet high to 5 feet high, 3.5 feet deep by 6 feet wide. I had the idea of insulating it all with foam board and throwing in my small fridge with its door open, which is only about 3 feet high (its small but not "mini"). Maybe circulate the cool air with a small fan inside the fridge.

It's occured to me that the back of the fridge generates heat. Its not a problem to have the back end of the fridge sticking out of the insulated portion of the closet so that its not contributing heat to the inside.

Has anyone tried a similar thing? Do you think the fridge will end up over-worked? I would love to use this closet for kegs and lager fermentation. Taps would look beautiful on the door of the closet.

Is this a good idea or should I look at another way of cooling the closet?

Cheers!

Experiment with it, and see if that keeps your ambient temperature where you want it. I think a few people have tried something like this, but there is a risk. Overstressing the cooling element in your fridge could make it freeze over.

But hey, if you can find a way to make it work, a closet kegerator would be pretty sweet.

Never seen a small fridge cool something quite that big. I suppose it might work if the space is insulated really well. Seems like it might put a bit too much stress on the cooling element.

Maybe just butcher a full size fridge? They can easily be had for Free-$50 on Craigslist.

ScottyT said:

Maybe just butcher a full size fridge? They can easily be had for Free-$50 on Craigslist.

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Now that's a pretty good idea. Wish I had thought of that.

It's occured to me that the back of the fridge generates heat.

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Check your fridge for condenser coil location.
Newer fridges have the condenser in the side and top walls and generate heat.

Cheers,
ClaudiusB

Another option that has been used is window or wall style A/C units.

I don't know much about fridge specs.. but here's mine.

Design Pressures: High-side 335 psi Low-side 140 psi
Refrigerant 135a Charge 2.0 oz Amps 1.05
Compressor 230 BTU per hour
Minimum compressor capacity 16 inch

Does this tell us anything about its potential performance?

Thanks for the replies

The 230 BTU/h cooling capacity is a bit low = 67 Watt, can work.

What you need to know is the insulation losses for your design, based on material and surface area.
The max ambient temp you will encounter.
The temp delta you require.



Cheers,
ClaudiusB

now I'm thinking a better idea would be using my chest freezer, its about 6 or 7 cubic foot. It would fit right under my stairs with a bit of clearance in the closet.

Question: Can a chest freezer operate lying on its side? Face-down, with the compressor and guts now facing up?

AFAIK all refrigeration units can only properly operate in the position that they were designed to do so. This is why you should let a fridge or freezer stand upright for several days before plugging it in, if it was transported on its side/back for some reason.

Edit.. i noticed you said you would keep the hotside out of the fridge.. it should work that way but wont get exceptionally cold.

And you may run into some problems if your chest freezer is not upright. but i have never tried to run one on its side.. so you may just have to let us know.

yeah... everything I've read on the internet tells me there's oil or something for the compressor that need to work with gravity.. requiring the freezer to be upright. That's not a problem though. With the lid off, it still will fit right under the stairs with a foot or so hanging out, letting me circulate air out of it. Setting it on its side would only be an extra convenience. I am going to try it this way. I'll be on to the project soon with a pic or two. It will be a unique project, but nothing very new

You just have to isolate the parts of your fridge that produce heat from the parts that produce coolth...?

Ooo thanks for posting Phlyan.. I did see the pics of your box in another thread. I looked to see if you had a thread for your build.. I wanted to ask: what is it you are using to seal the seams of your box? How low can you hold the temp?

It's very similar to what I want to do, but since I'll be cooling a bit bigger box, I am thinking to use my chest freezer instead.

Budzu said:

Ooo thanks for posting Phlyan.. I did see the pics of your box in another thread. I looked to see if you had a thread for your build.. I wanted to ask: what is it you are using to seal the seams of your box? How low can you hold the temp?

It's very similar to what I want to do, but since I'll be cooling a bit bigger box, I am thinking to use my chest freezer instead.

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I used a construction adhesive that comes in a tube (like caulk) and dispensed it between the seams of the rigid foam. They're tongue and groove so that helps too. It took exactly 1 tube to glue the whole thing together. Then around the top edge I ran a bead of spray foam and put the tape over it, then set the lid on so that it would form to the exact contours of the lid.

Temperature wise, it holds 38-40 on the far end, and 34-36 ish on the end closest to the fridge. Now, this is due to the fridge shutting itself down. If I had a way to override the thermostat I could probably get it colder but for me I don't need to.

PhlyanPan said:

You just have to isolate the parts of your fridge that produce heat from the parts that produce coolth...?

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I'm gonna do this in the summer, works pretty well?

magnj said:

I'm gonna do this in the summer, works pretty well?

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For me...it couldn't get much better. It took me like an hour to build, it's got more room than I have kegs, keeps things plenty cold, allows me to choose how cold I want something, and it costs about $8 a month to run. What's not to like?

Don't get me wrong, there's some improvements I have planned, but for ease of assembly and cost...I don't think I could have done much better. It cost me like $40 in insulation and glue and I had the mini fridge already.