Cold Box project advice..Calling all engineers!
 

I'm getting ready to embark on what I see to be a pretty ambitious project to build a cold box style kegerator into my already existing bar. I'm going to have to tear my baby apart a bit to make this work because I didn't design it with a kegerator in mind. Logistically, I believe that I have worked everything out from a construction perspective, but I have some worries about how successful this setup will be. I don't know if I will be able to sustain a cold enough temperature and whether or not the compressor of the fridge can handle it without burning out.

I have an older (but not crazy old) Haier mini-fridge that I'm guessing is about 4.5-5 cubit feet. (I would turn this into a kegerator, but even with modifications it's not big enough to hold 2 cornies because the compressor doesn't allow enough floor space.) Anyway, the interior dimensions of the cold box will be roughly 27"(W)X17"(D)X30"(H). That will add roughly 8 cubic feet for a total of 13. So will my compressor be able to handle 13 cubit feet if I insulate it with 2" R10 foam board and seal it up nice and tight?

I really want to make this work because having a cold box would allow me to expand my setup to as many as 6 cornies eventually if I choose to do so. If I do a conventional kegerator I won't be able to expand it. I put way to much time and money into my bar to scrap it and build a new one, and I don't have room for a keezer. BUT, I don't want to put all this time and effort into this and risk damaging my bar if it isn't going to work.

Any engineers out there who know more about this crap than I do have a theory? Or anyone with a similar experience?

I've seen collars built on the front between fridge and the door, side boxes, etc, but nothing that large. Depending on the actual specs of your compressor, just from shear volume, you'd be cutting it's life span at least in half due to the heavier load/cycles it would be doing. With proper circulation, it could probably cut it, but it sounds like a lot of stress on that compressor... Don't know you bar set up, but I'd cruise around on CL some more for apartment size fridge or mini freezer...

Here's what I did:

http://www.homebrewtalk.com/f51/4-6-cu-ft-fridge-10-1-cu-ft-fermentation-chamber-conversion-88554/

Its for fermenting ales so I don't know how it would work as a kegerator.

The biggest problem is my under bar storage is only 33" tall. If you notice all the freezerless fridges that are big enough for 2 cornies are 33" and change. If I could find an upright freezer small enough and use a temp controller, it would be less stress on the compresser; but I have yet to see a single one on craigslist or even new one that is the right dimensions. I guess I could always start with this and cross that bridge when I come to it.

Nice Work! Pretty close to what I'm trying to do except I'm not going to be able to reuse the door. You mentioned in your thread that you knew some people who could get them into the 30s. Do you know if they used a regular mini-fridge compressor or something more hefty? Any idea if they've had any issues?

I have seen pics where a guy took a small, upright freezer, removed the door, and attached it to a big foam box he made. Those little freezers are about the size of a 4.4 cf fridge.

He was building it into a bar, too. I think he made it big enough for 8 cornies, or a combination of sankeys and cornies.

Can't seem to find the threads, but search for "dorm" for dorm size fridge and "chamber" for fermentation chamber (search in titles only). I know this isn't what you're building but I swear some used them for lagering and even I thought as a kegerator. Sorry I can't remember where.

Yeah, it's probably the same one that I saw and am trying to rip off :) Other than the 1.7 cf freezers (which would probably be just as overwhelmed as my fridge) the next smallest one I can find is like this 5.0 CF GE at Best Buy. The problem is that it is still too big. The fridge/freezer itself had to fit in a 33"(H)X21"(W)X19"(D) space. This particular freezer exceeds it in every dimension.

my ge is a 1/16 under 33" model tax4dncawh the problem is you need ventalation which they say is 2" top and .5 on the side. thats because of heat release. wonder if you were able to make it one inch and used a muffin fan to pull head up and out. you would of course need to mut a whole in the counter top or you could possibly build something that would pull air through it. if you did build a chimney it would pull its own air through the chimney effect naturally. do you have any diagrams of the space you want to install one into? maybe we can come up with something to help out. remember when drawing it give some dimensions and whats on top

http://farm4.static.flickr.com/3130/...02d541d8_o.jpg

I used a freezer in my cold box build, but I know that forum member "Dude" used a mini fridge in his build and it keeps temp fairly well.

The main issue with the coldbox is to make sure and close any and all points that might leak air. The kegs and beer will help hold temperature much like a regular fridge holds temp better full of food than empty. I cold condition kegs in mine was well as serve them. I tap six and condition another 5 with room to spare. Those conditioning kegs provide a lot of thermal mass to help keep temperature.