Fully Temperature Controlled Fermentation Chamber for about $200

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user 40839

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A bunch of folks have asked (well, two) about a build thread for the fermentation chamber I posted on in the ebay aquarium temp controller build thread. Even though I REALLY didn't do anything that other people already haven't done, I'm happy to oblige in the hope that it helps folks out.

Credit where credit's due. The original build that completely inspired this was thomcat333's thread. This is a reproduction of his work, with a few minor modifications. Really really really, all credit goes to him. Mad brownie points to shushkiary for coming up with the idea of using the relay to control the fan.

fermentor02.jpg


fermentor03.jpg


fermentor01.jpg



I didn't take any pictures of the build in progress (too busy working on it!) unfortunately, but thomcat's build thread details it nicely - I was able to follow it without an issue (and I'm dumb as a rock). I just sized it bigger, because I want to be able to roll a sankey in there and ferment in that, plus I live in Northern California, so I wasn't too worried about having to control the box in extreme temperatures. If you live in Arizona or Alaska, where extreme ambient temperatures are more of an issue, your mileage might vary with a box this size. The insulation I used was 3/4" R5 R-Max stuff from Home Depot, which fit perfectly in the frame, and was easy to cut and work with.

A word of warning - like every project, this started out "cheap". I scored the mini fridge for nothing, literally a day after seeing thomcat's build thread, and thought SCORE! But honestly, by the time I bought the lumber for the frame, plywood for the exterior, laminated board for the inside, hinges and hardware for the door, plus a tube of liquid nails, tube of silicone, and screws, I could probably have scored an upright freezer on Craigslist - and not have the FUN three hours of delicate work (and not cut the ****e out of my fingers and hands) from gutting that fridge, plus the 3-4 evenings of putting the cabinet together after work. But there's something inherently groovy about having built this thing myself from scratch, and it made it a LOT easier punching holes for the heating pad and fan, knowing that there were no coils to rupture. But here's a rough breakdown of the cost:

Cabinet:
Lumber: (Four 1.5x1.5 furring strips, two 2x4) $17 (Local lumber store)
One sheet 8x4 1/4" plywood: $16 (Local lumber store)
One sheet 2x4 1/4" plywood: $9 (Local lumber store)
One sheet 8x4 3/4" RMax insulation: $14 (Home Depot)
Hinges: $4 (Ace)
Draw latches: $6 (Ace)
Two sheets 8x4 1/4" laminated MDF panelling: $22 (Local lumber store)
One tube liquid nails, one tube silicone caulk: $12 (Lowes)
Subtotal: $100

Control:
Ye Olde ebay aquarium temperature controller: $29.00 shipped
6x4x2 project box from Radioshack (a little tight, a bigger one might be better): $4.99
Rocker switch from Radioshack: $3.99
Two pilot lights (one blue, one red - neon 115v AC) from Electronic Plus: $12
Two three-port terminal blocks from Electronic Plus: $1 each or so.
Subtotal: $52

Fan Control:
Relay from Radio Shack: $8.49
12v Computer Muffin Fan: $5
Power Supply (old ac adapter): Free
Mounting Screws (4x 3.5" #10 screws, 12 nuts): $4
Subtotal: $17.49

Cooling is provided by the guts of an old mini fridge I scored for free.
The heating is provided by a $29.90 Brewer's Edge space heater pad from Williams Brewing which sticks to the back of the cabinet.
Subtotal: $29.90

Grand total: $199.39 (phew!)

So, once the cabinet's built, there are two areas of wiring that went on: the control box itself, and then another box at the back of the cabinet. The rear wire box is just a standard two-gang plastic junction box that I had lying around that houses a ton of wire nut connections, and the relay which provides power to a clipped female end of extension cord for the 12v fan.

So here's the wiring diagram. Basically, power comes into the junction box at the back via an extension cord that was clipped. (I cut it 6" from the end of the outlet, which I saved and used for the fan.) The control box, mounted on the top, has four wires heading down to the junction box - one black for power, one white for neutral, and then two more (I used red and blue tags on the wire, so I could tell them apart) which will provide power from the switch to the heater and cooler. While the control box is nice and neat, the rear junction uses copious amounts of solder and wire nuts, but they're tucked out of the way and hidden at the back, so I'm not worried about them.

wiring_fermenter_full.gif


Shushkiary explains the relay a lot better than I could, but basically tag one is always on unless there's power to the coil (7 and 8). Which means when the box fires the fridge guts, it also provides power to tag 2 because that's where the switch stays naturally. So when the fridge works, the fan works. When the controller fires the heater, it powers the coil which causes tag 2 to flip. Now it's in contact with tag 3, so there's power to the fan still.

That should make sense. Hopefully, at least. I understand if it doesn't, since it took a few reads and rereads of many posts and threads in order for me to figure it out - at which point a light went on and I thought "Oh yeah!" But if you have any other questions, let me know. (Hopefully someone who knows what they're doing can answer them, I probably can't.)
 
Where did you put the compressor and lines from the mini fridge at? It looks awesome by the way! Can you fit two carboys in there?
 
Where did you put the compressor and lines from the mini fridge at? It looks awesome by the way! Can you fit two carboys in there?
Aw, man! You're gonna make me go downstairs, and pull the thing out and grab a pic of it?!?
fermentor04.jpg


It was in REALLY bad shape when I picked it up - here's an actual pic of the fridge I got:

crap01.jpg
crap02.jpg


The freezer condenser itself was covered in mouse poo that took a while to scrub out. Basically, when I finished gutting it and scrubbing it out, I set it on my workbench and measured the height to the part of the line that the freezer unit was connected to. That told me how far my shelf had to be from the top.

And speaking of shelves, if I make one that I can pull in and out, I can actually get four carboys in there. (two fit on the floor, and I think I have plenty of room vertically to get two above them).
 
Nice work! I have a crappy mini fridge I need to get mounted in my ferm chamber, it's gonna get warm in my garage soon! The nice thing about that fridge you have is that the coils were already external. I need to cut the coils out of the fridge insulation on mine before I can mount everything in my chamber. Thanks for the pics.
 
A much easier way of doing this is to convert the dorm fridge into a chest fridge (http://www.instructables.com/id/How-to-Convert-a-mini-fridge-to-a-chest-refrigerat/) and build a collar similar to that of a keezer on it. A fan should be added to provide circulation as now the cooling element would be at the lowest point. The only problem I can visualize is the hump in the fridge getting in the way.
For folks doing 5 gallon batches, I'd agree - but I was planning on fermenting 10 gallons in a sankey fermenter, and lugging that thing in and out of anything chest-style wouldn't have worked!
 
I was planning on fermenting 10 gallons in a sankey fermenter

Are you confident that tiny compressor/evaporator is enough to cool such a large space (and volume of wort)? An equivalent sized upright freezer or fridge would have a much larger compressor and evaporator.
 
Mind if I ask where you got that really awesome deg C to deg F sticker? I'd love to use something similar to it, and printing one out on paper and taping it just seems.... lack luster, so I'd like to have one more like yours.
 
Mind if I ask where you got that really awesome deg C to deg F sticker? I'd love to use something similar to it, and printing one out on paper and taping it just seems.... lack luster, so I'd like to have one more like yours.
Did it myself in Quark, and printed them on Avery 3 1/3 x 4 shipping labels. Click here to snag a PDF of it, if you want to print 'em yourself... (or PM me your address, since I printed six and only needed one)
Are you confident that tiny compressor/evaporator is enough to cool such a large space (and volume of wort)? An equivalent sized upright freezer or fridge would have a much larger compressor and evaporator.
Agreed about the upright freezer. If I had to do it again, I'd probably just keep a lookout on Craigslist as I said, since I've seen reasonably sized ones on there for what I paid to build the cabinet, $100 or so. (although it would have made mounting the pad and the fan a lot trickier, having to drill through walls full of coils, unless I did everything through the door).

Being where I am, the temperature (particularly in the garage, where this is living) rarely gets above 80 degrees, so I'm expecting the condenser to not have to do a lot of work. Like I said tho, if you're in some place like Arizona, YMMV with that. The main issue would be the initial temp, getting it to fermentation levels. Once it's there, I'm absolutely confident that won't be an issue.

I did do a test run before I popped that apfelwein in there with 73F water, and set the chamber to 10C / 50F and it hit it in 73 minutes, with an external ambient temperature of 67F. Once there, the compressor only came on for a total of about 5 minutes each hour (I have it set to a 0.5C differential) to keep it at temp.

It might struggle to lager in the middle of July, but since I hate lager... ;)
 
I found a good working fridge for $30 on craigslist and plugged in my Ranco. Done.
But that was lucky, if you were really looking for one they are not around.
The day I brought the fridge home, my neighbor said they were getting a new fridge and asked if I wanted their old one.
 
Thanks! I'll just get a label sheet and print it my self, the shipping to get one to me would cost more than the whole sheet its self, but thanks for the offer!
 
I found a good working fridge for $30 on craigslist and plugged in my Ranco. Done.
But that was lucky, if you were really looking for one they are not around.
The day I brought the fridge home, my neighbor said they were getting a new fridge and asked if I wanted their old one.
Yup. Anytime I DON'T want something, I see them for sale absolutely everywhere - but the second there's something I need, they become rarer than an alcoholic mormon.

Case in point, about a month after I finished this, my wife decided she wanted a new fridge for upstairs, so we got one. And since there was no room in the garage for the old fridge, it got hauled away. Still kicking myself over that, I should have pulled out the heating pad and control box from this, and wired it up.
 
Just as an update for folks - don't @#$# bother. I just took a sledgehammer to this thing a week ago, after picking up a 15 cu ft upright on Craigslist for $100.

If you DO build one of these, don't trust ANYTHING to be waterproof. I had a couple of overflows with my blowoff tubes, and even though everything was caulked and sealed, the wood slowly turned to mush, and the laminated sheets on the inside turned to crap.
 
if your still watching this thread, where did you attach the rocker switch for the control box I dont see it in the diagram.

thanks
 
that was my thought rudu81, i'm looking at inbeding this kind of set up in the front of my keezer collar if i go with a collar. I have been looking at going with a coffin box on top similair to jester's and wiirng in two box fans: one into the box and one out of the box. I'm working on my conceptual idea at the moment.
 
I am in the middle of a similar build using a relay so I purchased the Radio Shack version you used. With that said I noticed the relay is numbered differently than what you have numbered on your diagram. Do I go by the numbers or by the layout? Thanks..

Relay Layout is as follows..

3-17-2011 7-35-30 AM.jpg
 
I am in the middle of a similar build using a relay so I purchased the Radio Shack version you used. With that said I noticed the relay is numbered differently than what you have numbered on your diagram. Do I go by the numbers or by the layout? Thanks..

Relay Layout is as follows..

The numbers would change. Cool hot would go to 1 still, the fan hot would go to 5, the heat hot would go to 3, and the 7/8 would stay the same... That is assuming that the diagram is showing the normally closed operation of the relay (no current through the coil), which it usually is.
 
Do you have a part number for the three-port terminal blocks from Electronic Plus? I'm an electronics moron trying to copy your build, I may be in over my head.
 
Hey anybody have luck with the stc-1000 temp controller? i order this on from ebay and when it arrived i realized was 220v and not 110V
 
Hey anybody have luck with the stc-1000 temp controller? i order this on from ebay and when it arrived i realized was 220v and not 110V

I have a system built around this controller (110v) and used this thread. Getting a 220v controller seems to happen on occassion. Check the last couple pages for posts and remedies, or do a search of the thread.

Good luck!
 
I am building a chamber that will hold 3 fermenters based on this design. Only thing I can't find is the 1/4" laminated mdf. I've checked lowes, home depot, and 84 lumber. Not really sure what to use in place of it, except maybe plain ol' plywood, (painted to make it water resistant). Any ideas?
 
OK. I'm giving this type of Temp. Controller a try. I understand the layout for the control panel. Couple of questions though. 1) Did you wire up outlets for the heater and cooling side or did you wire them directly? 2) Do you have any pics of the back of the cabinet that shows how it's all wired up? Where are the Wire Nuts?
 
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