My Mini Fridge to Fermentation Chamber Build

[chumpsteak]

A buddy and I just started brewing a couple months ago and have officially gone off the deep end with this new hobby. After 2 extract batches we went to all grain. After 1 all grain batch we bought a new 15 gallon kettle. After the 4th all grain batch we decided we needed somewhere better to ferment than the exercise room of his house, and so the idea of building a fermentation chamber came up.

My wife didn't really like the idea of another fridge/freezer in the garage, so after looking on the HBT forums I decided to clean the crap out from underneath the work bench and build a chamber there.

Step 1 was finding a cooling source. Since my garage gets to around 100 degrees some days in the summer it was important to find something big enough to cool yet still fit under the workbench. I decided a 4cf mini fridge ought to work so I set out looking for one.

After a couple weeks of looking I got really lucky and got an almost brand new frigidaire mini fridge for 50 bucks on craigslist. The guy had just spent almost 200 on it 2 months ago but needed to get rid of it.

Its a super nice mini fridge and I feel kind of bad about basically destroying it, but it had to be done. If I was ready for kegging I'd have built a kegerator out of it instead.

Anyway, the next weekend I went to home depot for materials and got to work.

My love 2 stage controller will be here this week, so I hope to have it installed and controlling temps by next weekend.

The space is a little bigger than I originally wanted, but I decided if I made it as airtight as possible and insulated it really well with 2in foam it would probably work. I can fit at least 5 buckets/carboys in it and yesterday I had a jar of water cooled down and stabile at 41 degrees with a fridge temp of 37 in a 85 degree garage. Not too bad considering I really only built it for fermenting ales at 64. With the fridge set to it's highest temp setting the chamber stabilizes around 57 degrees and the compressor barely runs.

Right now I only have 1 pc fan running in there, but I ordered 2 more higher cfm fans to hopefully circulate for air and make the chamber more efficient at cooling. Also ordered a little personal ceramic heater that will be used later this year to help maintain temps when the ambient temp drops.

Anyway, thanks for looking and let me know if there are any questions.

I'd also like to thank everyone who posted their builds and provided lots of ideas and inspiration for this project. Almost none of the ideas used to build this chamber were my own. All were pretty much taken from this forum. I'm new to this hobby, but thanks to you guys I feel like I've already learned so much.

 

[brewguy82]

pretty cool...no pun intended

 

[Rundownhouse]

Could you post some more details about how you built the door in?

 

[chumpsteak]

The door surround is just roofing metal from the home depot. The door already has a magnetic strip in the weather seal so it just needs something metal to grab onto.

The hinges are the original ones that came on the fridge, but I put the top one on bottom because it was more robust, and I hacked up the bottom one and made a new bracket out of it to mount the top of the door. Basically cut it in half, bent it so that it stuck out the right distance, and drilled 2 new holes to mount it. Not that hard if you put the door in the hole and then figure out how far your brackets need to stick out. Oh, and the bottom bracket is mounted in a block of wood I cut down to get the door at the right height. The door opens and closes super smooth and shuts tight. In fact I got in there last night (yeah it's that big) to do a little more finish work and when I shut the door it was like being in a vault. It seems pretty air tight.

Let me know if you need pictures of the door brackets and I'll see what I can do.

 

[nootay]

Looks great man! I'll be building something similar in the next couple weeks. Did you leave an airspace gap between your insulation and outside frame? I think I remember reading somewhere that a gap makes it insulate better, but don't now why and if that is even true. Is the part you built actually connected to the fridge? My brew room isn't completely built yet, so if I build a fermentation chamber I'll probably have to move it a few months down the road. Not sure if moving it would possibly break it apart or not. I also love your idea for the door! I'll have to figure that out as well

 

[chumpsteak]

forgot to mention I used 2x2's to build the door frame. I attached it to the 3/4" plywood and then foamed around the opening with spray foam and caulked all the seams. Then once I had the plywood screwed into place I caulked everything again and then put aluminum tape around the door opening including the roofing metal that's inside the door frame.

 

[chumpsteak]

Nootay,

There is a 1.5" air gap between the 2" insulation panels and the walls. Basically the thickness of the 2x4's I installed to give the foam something to stick and to get the foam around the house foundation.

The fridge is only attached by caulk. I set the front half way on a 2x4 and built a plywood surround that fit pretty tight. I then caulked everything in place. The idea was to be able to remove the fridge if I had to in case the compressor dies or something. I'd basically have to cut through 3 inches of caulk, foam, and plywood, but I think I could get it out without wrecking the box if necessary.

As for the door, I'd like to take credit for that, but I got the idea from a couple of other builds on these forums. I liked the idea and figured the door was always going to be the hardest part to make air tight, so why not do it like the fridge manufacturers do?

 

[nootay]

can i use osb instead of plywood? i have quite a bit of 5/8" osb

 

[chumpsteak]

I don't see why not. I'm no Thermodynamacist, but I don't believe the wood really adds any insulating properties to the fermentation chamber. The foam board along with lots of calk, spray foam, and aluminum tape help to keep the thing air tight and well insulated. The plywood or OSB is just used for framing and structural purposes.

 

[nootay]

so did you lay the foam boards directly across the 2 x 4's on the floor? will the weight of a full bucket not break the foam boards in the gap between 2x4s? im not sure how stiff that stuff is. how big is the gap between your 2x4's on the floor?

 

[AnchorBock]

Im beefing up my chamber and this is essentially what im going to do, yours looks great! I was at a loss for how to get the door to seal, ur idea is perfect. What are you using above the insulation for the floor and walls?

 

[chumpsteak]

so did you lay the foam boards directly across the 2 x 4's on the floor? will the weight of a full bucket not break the foam boards in the gap between 2x4s? im not sure how stiff that stuff is. how big is the gap between your 2x4's on the floor?

It's not in the pictures, but I laid more 2x4 pieces on the floor of the garage before I put the foam down. Between the 2" foam and the 2x4's and the vinyl covered 3/8" paneling on top the floor is plenty rigid. I can sit in there without breaking it. The foam by itself might be pushing, although it is pretty sturdy stuff, but it would definately dent.

 

[nootay]

good deal, i believe i am going to do the same. i started construction of mine today. got all the framing done and have started the osb on the outside. where did you get the 3/8 vinyl covered paneling? is that exactly what its called? i need to find something similar to mine. i was thinking about a sheet of OSB over the foam, then finding some scrap linoleum to lay over the osb.

 

[chumpsteak]

Im beefing up my chamber and this is essentially what im going to do, yours looks great! I was at a loss for how to get the door to seal, ur idea is perfect. What are you using above the insulation for the floor and walls?

If you're referring to the white stuff, it's some white vinyl covered gypsum or something like that. I think it's 3/8" and it comes in 4x8 sheets at the home depot. it's like 10 bucks a sheet and I used 2. It covers all walls/floors/ceiling. Wanted to protect the foam and also make the whole chamber somewhat waterproof in the event of a spill or blowout.

I used other builds as inspiration for the door. I just couldn't see how I was going to be able to make the door airtight and insulated well and still keep it easy to use. The fridge door solved the problem. I get a really good seal and it's super easy to open and close.

 

[chumpsteak]

good deal, i believe i am going to do the same. i started construction of mine today. got all the framing done and have started the osb on the outside. where did you get the 3/8 vinyl covered paneling? is that exactly what its called? i need to find something similar to mine. i was thinking about a sheet of OSB over the foam, then finding some scrap linoleum to lay over the osb.

I think you could probably put just about anything over the foam and it would work as long as the foam is well caulked and even aluminum taped. I originally wanted to use melamine, but I couldn't find any in thin enough sheets or cheap enough. I found the white vinyl covered stuff at home depot and the price is right. I'm really happy with it, buckets/carboys slide on it easy enough and it looks finished inside. This thing is basically part of my house now and I wanted it to look nice.

 

[nootay]

i am still unsure when it comes to the door. I made my framing that connects to the fridge 50 inches long. With this, i can fit 3 fermenters in to the chamber. Do you find that with the fridge door you have to pull fermenters out to put more in? i was thinking of making one large door so that i could easily slide stuff around and not have to take anything out. only issue is it will not seal as well as the fridge door idea.

 

[chumpsteak]

I have yet to actually put any fermenters in mine since I just got it done last week. I put the door on the left side of the chamber so I'd have access to the fridge and fans and heater and whatnot that are in or will be in the actual fridge. There is a couple feet to the right of the door that will hold fermenters, so I will most likely have to do some shuffling when I add/remove fermenters to the chamber. Didn't seem like a big deal to me, maybe it will when I actually start doing it. However having the vinyl on the floor will help the fermenters slide and should make manuevering much easier. Having the door not be the overwhelmingly weekest link seemed like the more important thing to me.

 

[Fantastical]

Very nice!

 

[gilby_7]

Very cool! I would like to do something like this in my house but since it's worth less than a third of what I paid for it I'm trying to dump it.

 

[chumpsteak]

I got the Love TSS2-2100 controller wired in and a couple more fans running now and the chamber seems to be doing very well. I have a bucket of water in there now and I'm able to keep it at a pretty constant 66 degrees with the compressor only kicking on a couple times an hour. It's 95 outside here today and at least 85 in my garage so I feel pretty good about how it's performing. Just need to figure out the best settings for the love to keep the compressor from running too much, but it's able to completely cool down between runnings, so it's probably ok right now. Will update with pics of how I mount the controller soon.

 

[chumpsteak]

Finally received the last of the necessary parts today and finished the chamber:

Mounted the Love 2 stage controller

The fans and heater in place. The fans are angled up at about a 30 degree angle to blow air across the fridge ceiling. This pushes cold air into the chamber and also almost eliminates condensation. The heater I ordered from home depot for under 20 bones. I taped it down and installed a glass shelf above it to protect it from any drips.

Shot of the probe taped to a bucket full of sanitizer. This method keeps the fridge from cycling too often.

Here's the Love controller wired to an outlet. The top is for the fridge and the bottom is for the heater.

Last shot shows how well everthing integrated into my garage. Still room under the workbench for all my brewing equipment. I'm happy and SWMBO is happy. At least until she see's the credit card charges.

Considering smoothing the plywood with something and painting it, but that sounds like more work. Not really minding the plywood right now. It is my garage after all.

I have the day off tomorrow, so I'm making beer. Can't abide by an empty chamber any longer.

 

[chumpsteak]

5 gallons of Newcastle clone is now bubbling away at a rock solid 66F in the chamber

 

[lewybrewing]

Nice...Im shooting for something close for my chamber. Thanks for the great write-up.

 

[IrregularPulse]

Great work. This is what I'll be doing with my bar build whenever motivation kicks me in the butt. or the wife. whichever happens first. Any picture to the left and at an angle of the last one? Is the mini fridge completely enclosed?

 

[xeno]

Great thread. Controlling fermentation temp is my next big project. I too would like to know if the fridge is completely enclosed. Looks very nice and seems well integrated into the house.

 

[IrregularPulse]

Any chance of a closeup of how your door hinges are mounted? I'm starting work on mine tomorrow after a talk with the wife and design simplification last night.

 

[chumpsteak]

Thanks for the nice comments guys.

The mini fridge is not enclosed. The sheet of plywood that the temp controller is mounted on is just hiding it. There is about 6 inches of open air on both sides and the back of the fridge is open. The sides get very hot when the compressor is running, so you don't want to enclose them. The fridge documentation said to leave 6 inches open on the sides and 4 inches in the back I think. I'll go get you some close up pics of the door hinge setup.

 

[chumpsteak]

Here's a shot showing the back of the fridge. The pic makes it look like the side of the fridge is right against the back wall, but it's not. There's about 6 inches back there.

Top Hinge closeup. I basically hacked up the original bottom hinge of the fridge. Had to cut it down, bend it, and drill some new mounting holes in it. Maintained the original post and plastic bushing.

Bottom Hinge. This was the original top hinge of the fridge. The best way I could think of mounting it was to cut down a block of wood to the exact height I wanted and then mounted the hinge to the block of wood. Not really a hinge I guess, it's just a post mounted to the block of wood.

Put some damp rid in there yesterday because there was some condensation on the ceiling of the fridge due to the coils and the fermenting beer. Checked this morning and there is zero condensation in there. Very happy with it.

 

[63belair]

DampRid FTW!

Excellent build, thanks for posting pictures!

 

[IrregularPulse]

Nice, thanks for the pics.