Cold Box project advice..Calling all engineers!

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rudy0498

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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...
 
MoRoToRiUm said:
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...
Click to expand...

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.
 
-TH- said:
Here's what I did:

https://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.
Click to expand...

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.
 
rudy0498 said:
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?
Click to expand...

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.
 
Cpt_Kirks said:
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.
Click to expand...

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.
 
rudy0498 said:
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.
Click to expand...

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

3131421875_d502d541d8_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.
 
I'm just throwing this out for conversation... and as an engineering student, I'm obligated to do so.:D My first thought was... yea it will probably work, but, I can be pretty lazy...so I asked myself the "why" question.:confused:

Hundreds of bars across the country store their beer in coolers in the basement or adjoining rooms of the bar. They run lines to tower taps or wall taps. I gotta ask the question: is this the only available space you have for a kegorator? If not, is the closest space close enough to run lines for a tower or tap wall?

My brother is in the heating, cooling, and appliance repair industry. I've talked with him many times about modifying freezers or fridges to do a myriad of tasks from cooling kegs to cooling wort. We've always settled on the fact that modifying appliances is risky at best. Either the equipment needed to control the operation will shorten the life of said cooler (like the ranco temp controls) or the cost to purchase the right equipment negates the project altogether.

If the space you have under your bar is the only space available, then by all means, build the cold box. If you can go another route, that would be the advice I would offer.

BTW, if by chance you build the box and you need technical questions answered by a professional in regards to the appliances, PM me and I'll get you my brothers info.:mug:
 
i have see alot of modified fridges and other things... being an egineering student and an HVAC guy i dont see whats wrong with modifying a existing fridge providng you are carful... it can limit the life time of teh applience but thats the point of making one yourself for less money then buying a new one... one you make has personal value and is not as obsessive as a store bough beauty which you morgaged your soul to buy... That said... be smart about it... I saw a under counter keg storage which i found rather effective... the owner have taken his bar counter to and drilled holes in and mounted taps and directly below was an old style chest freezed which was rather tall but not very wide front to back (maybe 44" by 32") he laid it on its front side so you could bend down and life the lid like a door. Then he used a stud finded to track the freon lines which ran though out the freezer's back wall and drilled 1.5" holes in the back where he would not hit the lines (it also helped he had a diagram where they were, a simple coil operated freezer would not have this trouble but they tend to be bigger, this one was real old school). The he dropped his taps through the counter and top hole. filled around the holes in the freezer with food grade low temp resistant sealent and food grade insulating foam. After sealing up he added vents along the bottom front of the bar which vented the heat from the freezers exterior cooling coil (this is actully quite nice because he has his bar in the basement and it can be chilly down there and a warm breeze on your feet feel good) He but in a cupboard next to the setup where he put three 5lb CO2tanks and all his pressure controls for each 6 taps (the freeze was about 6-8 feet long side to side, which was why it was so thin front to back) All the pipeing for the regulators was run along the now top of the cold storage/taping freezer... I drew up a picture in paint but i cant figure out how to post it now and that has somthing to do with being a bit tossed... well ill try in the morning

Cheers

 
pen25 said:
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
Click to expand...

I googled that model number the only thing I can find are parts. So it may not be sold anymore. I did find a couple freezers shorter than 33" but the depth of the fridges were way too much. I found one 2.3 cf mini freezer that would fit, but was a brand I'd never heard of and was $250 after before shipping which would probably be outrageous. The ventilation idea sound pretty doable. As you can see in the pictures below it's a 2-level bar top. I could stick a muffin fan in the corner of the lower bar top and nobody would really see it. Here are a couple pictures of the bar (please ignore the Christmas clutter and dustiness :)):

This a side view of the compartment I would put the cold box in. The long panel on the left would be the insulated portion of the cold box. The short panel (in the corner) would be where the fridge is. The interior dimensions of the fridge compartment are 20.5"(W)X20.5(D)X33"(H). The fridge I have is 19-5/8"(W)X17"(D)X33"(H). The 33" Height is to the top of the 2X4 frame, so it's actually and 1-1/2" higher in the middle. I could carve our enough of the 2X4 to get a ventilation hose hooked up to the fan.

DSC02118.JPG


Behind view of the Bar view. As you can tell it's L-shaped. The cold box would be in the short side of the L.

DSC02119.JPG
 
mmb said:
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.
Click to expand...

Glad you chimed in. Seeing pictures of your cold box in another post is what gave me this idea :). Glad to hear someone has had success with a fridge in this manner other than for a fermentation chamber. You did give me an interesting idea. I could use some other things that hold temperature better to fill in some of the excess air space (like a bucket or bottles of water or something), which would lessen the stress on the fridge. This plus proper ventilation make me feel a little more confident that this could work.
 
Seabee John said:
I'm just throwing this out for conversation... and as an engineering student, I'm obligated to do so.:D My first thought was... yea it will probably work, but, I can be pretty lazy...so I asked myself the "why" question.:confused:

Hundreds of bars across the country store their beer in coolers in the basement or adjoining rooms of the bar. They run lines to tower taps or wall taps. I gotta ask the question: is this the only available space you have for a kegorator? If not, is the closest space close enough to run lines for a tower or tap wall?

My brother is in the heating, cooling, and appliance repair industry. I've talked with him many times about modifying freezers or fridges to do a myriad of tasks from cooling kegs to cooling wort. We've always settled on the fact that modifying appliances is risky at best. Either the equipment needed to control the operation will shorten the life of said cooler (like the ranco temp controls) or the cost to purchase the right equipment negates the project altogether.

If the space you have under your bar is the only space available, then by all means, build the cold box. If you can go another route, that would be the advice I would offer.

BTW, if by chance you build the box and you need technical questions answered by a professional in regards to the appliances, PM me and I'll get you my brothers info.:mug:
Click to expand...

unfortunately space is tight and my house is on a slab. So an alternative location with lines running really isn't an option. As I get closer to doing this I may take you up on the offer asking your brother some questions. Thanks!
 
BrewinJack said:
i have see alot of modified fridges and other things... being an egineering student and an HVAC guy i dont see whats wrong with modifying a existing fridge providng you are carful... it can limit the life time of teh applience but thats the point of making one yourself for less money then buying a new one... one you make has personal value and is not as obsessive as a store bough beauty which you morgaged your soul to buy... That said... be smart about it... I saw a under counter keg storage which i found rather effective... the owner have taken his bar counter to and drilled holes in and mounted taps and directly below was an old style chest freezed which was rather tall but not very wide front to back (maybe 44" by 32") he laid it on its front side so you could bend down and life the lid like a door. Then he used a stud finded to track the freon lines which ran though out the freezer's back wall and drilled 1.5" holes in the back where he would not hit the lines (it also helped he had a diagram where they were, a simple coil operated freezer would not have this trouble but they tend to be bigger, this one was real old school). The he dropped his taps through the counter and top hole. filled around the holes in the freezer with food grade low temp resistant sealent and food grade insulating foam. After sealing up he added vents along the bottom front of the bar which vented the heat from the freezers exterior cooling coil (this is actully quite nice because he has his bar in the basement and it can be chilly down there and a warm breeze on your feet feel good) He but in a cupboard next to the setup where he put three 5lb CO2tanks and all his pressure controls for each 6 taps (the freeze was about 6-8 feet long side to side, which was why it was so thin front to back) All the pipeing for the regulators was run along the now top of the cold storage/taping freezer... I drew up a picture in paint but i cant figure out how to post it now and that has somthing to do with being a bit tossed... well ill try in the morning

Cheers

Click to expand...

It's going to be a pretty simple really. I'm just removing the door and strapping it to the side of the cold box. No drilling or jeopardizing the coils. Just limited air space/ventilation for the compressor and added volume for it to cool.
 
BrewinJack said:
I saw a under counter keg storage which i found rather effective... the owner have taken his bar counter to and drilled holes in and mounted taps and directly below was an old style chest freezed which was rather tall but not very wide front to back (maybe 44" by 32") he laid it on its front side so you could bend down and life the lid like a door.
Click to expand...

I just spoke with my brother about the "chest freezer on it's side" idea. He said unless the guy re-oriented the compressor and the lines, it might work for a little while, but he would soon be replacing the unit. Compressors need to be oriented the way the manufacturer puts them in. He said running a chest freezer on it's side would be akin to taking your lawn mower and turning the engine sideways.... it would work... but not for long. The compressor has oil for lubrication and cooling, if you turn it on it's side, the valves would not work properly and the compressor would over heat very quickly.

When I hauled my keg fridge home (on it's side) I had to wait for a few hours for the oil to drain into it's natural position to avoid burning up the compressor.

just food for thought
 
Seabee John said:
I just spoke with my brother about the "chest freezer on it's side" idea. He said unless the guy re-oriented the compressor and the lines, it might work for a little while, but he would soon be replacing the unit. Compressors need to be oriented the way the manufacturer puts them in. He said running a chest freezer on it's side would be akin to taking your lawn mower and turning the engine sideways.... it would work... but not for long. The compressor has oil for lubrication and cooling, if you turn it on it's side, the valves would not work properly and the compressor would over heat very quickly.

When I hauled my keg fridge home (on it's side) I had to wait for a few hours for the oil to drain into it's natural position to avoid burning up the compressor.

just food for thought
Click to expand...


Yup, he had me reorient it for him... I was in a hurry and didnt mention it... your right... sorry for the mistake

Cheers
 
I just wanted to follow up for everyone that helped me out. I went ahead and did the cold box. Here are a few pictures....I didn't take too many "in progress" pictures...just before and afters:

Here's the half of my bar that I'm putting the cold box in. The 2 sides of my bar split apart and the bar top sits on dowel rods. The fridge goes in the side of the left. I had to trim down those 2X4 and rip out the floor to fit the fridge in. I also put a muffin fan in the top that will ventilate the heat off of the compressor out holes under the bar top.

DSC02121.JPG


So here are a few of it all put back together. I used 3 sheets of 3/4" R4 insulated foam board on all sides (and the door). The door was the hardest part to get a tight fit and be able to open it. I had to shave a little at a time off of the side to get it to fit:

DSC02130.JPG


ignore the sloppy duct tape work

DSC02129.JPG


I decided to do a test to see how cold I could get it. I think it's safe to say it gets cold enough:

DSC02123.JPG


Well that's it. Thanks for everyone's advice. I don't think I would have been successful without it, and may not have even attempted it.
 
Hi,

I have embarked on the same type of project, for the same reasons: bar in basement with no space for a larger freezer or fridge. I bought a new Danby (same as what they use to make their kegerator as far as I can tell). I plan to reuse its door as the door for my cold box.

How has your setup held up over the last year+?
 
or31acres said:
Hi,

I have embarked on the same type of project, for the same reasons: bar in basement with no space for a larger freezer or fridge. I bought a new Danby (same as what they use to make their kegerator as far as I can tell). I plan to reuse its door as the door for my cold box.

How has your setup held up over the last year+?
Click to expand...

I did a similar project where I used the door from the fridge. It has worked out really well. Check it out if you're interested: https://www.homebrewtalk.com/f51/4-6-cu-ft-fridge-10-1-cu-ft-fermentation-chamber-conversion-88554/
 
TH,

Very, very nice job. I am plannig to do the same thing with flashing so the door seal will work. I had not thought of usig magnetic strip to hold the fridge to the box though; very ingenious!

Have you tried taking the temp down to beer dispensing levels yet? And any update on the compressor cycling?
 
or31acres said:
TH,

Very, very nice job. I am plannig to do the same thing with flashing so the door seal will work. I had not thought of usig magnetic strip to hold the fridge to the box though; very ingenious!

Have you tried taking the temp down to beer dispensing levels yet? And any update on the compressor cycling?
Click to expand...

I can't help you much there, I've only used it for fermenting ales so far and for that the compressor runs very infrequently - except when I open the door to lovingly check on my fermentors (which is often of course).
 
mmb said:
pink foam for insulation covered with the pebbled shower board available at HD/Lowes

Sealed with silicone and waterproof foil tape
Click to expand...

Well, I'm proud of myself -- that's exactly what I thought it was! Another GREAT idea -- I was thinking of using 1/4" melamine board, which is a PITA to work with. This will be much better.
 
rudy0498 said:
I just wanted to follow up for everyone that helped me out. I went ahead and did the cold box. Here are a few pictures....I didn't take too many "in progress" pictures...just before and afters:

Here's the half of my bar that I'm putting the cold box in. The 2 sides of my bar split apart and the bar top sits on dowel rods. The fridge goes in the side of the left. I had to trim down those 2X4 and rip out the floor to fit the fridge in. I also put a muffin fan in the top that will ventilate the heat off of the compressor out holes under the bar top.

DSC02121.JPG


So here are a few of it all put back together. I used 3 sheets of 3/4" R4 insulated foam board on all sides (and the door). The door was the hardest part to get a tight fit and be able to open it. I had to shave a little at a time off of the side to get it to fit:

DSC02130.JPG


ignore the sloppy duct tape work

DSC02129.JPG


I decided to do a test to see how cold I could get it. I think it's safe to say it gets cold enough:

DSC02123.JPG


Well that's it. Thanks for everyone's advice. I don't think I would have been successful without it, and may not have even attempted it.
Click to expand...

what is that thing that is covered in duct tape???
Great build by the way. Thinking of doing the same. is it still working?
 
i just scored this 33" mini freezer off of craigslist. I am going to use this for a similar coldbox and make it a little larger. I figure if a mini fridge works, a mini freezer will work with less stress..

freezer.jpg


freezertag.jpg
 
Ok. Just got this freezer all cleaned up and realized the coils run through both of the shelves. Any ideas on how to move the shelves and bend the coils so I can have a useable space??
 

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