Fermentation Chamber build, witty title coming soon.

[CU_tony]

At this point the only thing left to do is dry/weatherstrip and add some hinges. Ive got two temp controllers so I will be able to monitor different areas at least and I hope to try and take regular measurements on performance.
That being said worst case scenario it shouldnt be too hard to modify this design if my minifridge wont work.

Onto a picture! Here i have a before and after of the danish oil treatment. Time for this to dry and then get hinged up.

 

[CU_tony]

Door is on, mini-fridge fits, time for some stripping... of the weather variety.

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[CU_tony]

I've got the chamber setup and a temp controller hooked up high and low so I can monitor temp changes for the next few hours.

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[CU_tony]

The test results last night showed that while the unit wasn't able to cool the large volume of air quickly, once the test volumes reached target temp they stayed there.
I brewed today and below is a pic (pre blow off tube) showing a full carboy in the front at pitching temp and a carboy of water in the back at ~64 to help maintain a thermal mass.
I imagine once I get some bottles in the top for cold conditioning that will help to maintain the system temps.
I may make a graph of the temp values but if not I will keep posting if this works of if it's a bust.
I also added a second fan, and may add a third or add a 12v power supply to drive these a little harder.
Lastly I added a 15" tall removable piece of insulation to sort of prevent some of the "cold" from falling out when I peek at airlock activity.

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[lump42]

To slow the cold air flowing out when you open the door, you can also just add empty styrofoam coolers or closed cardboard box to fill in empty spaces until/between it isfilled with brews.

 

[CU_tony]

Whelp, I done ****ed up! I had the fridge plugged into the secondary temp controller on the water jug and since its the new inkbird wifi module (that still hasnt worked on wifi for me) I didnt realize that you set a high and low temp instead of a target and a variance.
Anyways, last night when I went to bed the carboys were 63.9 (water) and 66 (wort)
When I woke up the temps were 67.8 (water) and 68.7 (wort) and after investigation I found that while I set T1 to 64 I had T2 set to 68 on the new controller... a MUCH wider gap that I want and it has since been rectified.
In the last 3.5 hours the temps have dropped back to 66 (water) and 66.2 (wort) so while its a slow beast, it goes to reason that sometime last night the water carboy (which was in control) hit its target of 64 and then turned the fridge off for entirely way too long!

Im working on building the removable "shelf" so that I can place the active carboy halfway into the minifridge which should help keep the active fermentation in check.

I like your idea to fill the volume of the chamber when not in use Lump, I think Ill scab together some foam scraps into blocks to help with this, and Im hoping that once testing is through Ill comfortably be able to move a case or two of beer into long term storage in the 60s and I think that thermal mass will help to maintain (consistent) temps.

Just so yall know Ive never had the intentions of using this chamber for cold crashing or lagering, so even if the chamber can only maintain ~12d less than my house temps Ill consider it a success as I wont be fermenting at 76/room temp

 

[tracyk]

Yeah, that is all that I use mine for. Just for fermenting ale, not lagers. I usually fill my extra area up with bottled water just to maintain the mass, so the compressor does not need to work so hard.

Looks great though! Happy fermenting!

 

[CU_tony]

Here is the chamber after I added a 3gal carboy on the 4th, I still have a carboy of water in the back for stability.
The carboy on top is the controlled one and has stayed within 1 degree of 64, the 3 gal carboy has consistently stayed around 69 which is actually the low end of that kits recommended range. This weekend I'll rotate the upper carboy and add a new one up top. I'm hoping that once the wort stops generating heat from vigorous fermentation that the lower level will stay cooler compared to the current 3gal that is vigorously fermenting below now.

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[CU_tony]

The next major steps involve lighting and probably a raspi to control this vs my two inkbirds

 

[CU_tony]

Another week, another brew! The temperatures for the chamber stabilized as fermentation calmed down. I moved batch 7 down below with batch 8 and now batch 9 is taking the top spot. I'll enjoy seeing how the temperatures change with two stable carboys and one soon to be vigorously fermenting carboy.

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[Transamguy77]

I'm glad things are working out for you! It looks really good. You've inspired me to revisit mine to figure out why it won't keep temps like yours does.

 

[CU_tony]

As an update, with three "active" carboys in the chamber the temps on the newest batch #9 are remaining stable as fermentation is vigorous.
Batch #7 (8 days old) was rotated to the lower rearmost position and has stabilized around 66, which i consider an acceptable amount of deviation from the chamber setpoint of 64 currently.

Thinking on the design, with my current 5 and 3 gallon carboys, its nice to be able to use the large tube for a blow off with minimal kinking due to height of the chamber, but for efficiency sake I would probably chop a few inches off the overall height and deal with having to be more creative regarding blowoffs for the lower shelf.
Also I could have made the chamber thinner to accommodate the milk crates more snugly, however I primarily just wanted to match the fridge dimensions.

In the coming weeks I plan to add lighting, some more fans, and hopefully a rasberry pi so I can actually have useful consistently logged data to interpret.

@Transamguy77 Id love to offer any help I can because I think that this is a great design for people that dont have the roughly 1/2 a room you need to dedicate for a typical chest freezer fermentation chamber.
Lastly, and this may make a huge difference, I have my chamber inside my house where it never gets hotter than 78, if it were outside in a garage Im almost certain the poor little thing wouldnt cope well. However I built this to be a minimal presence in a room, and moving forward I have some more aesthetic design choices in mind.

 

[smitty8202]

very nice build. have you thought about having it only one level? you could mount the fridge on the side reducing the area the cold air has to flow and my have more consistent temps. Just an idea

 

[CU_tony]

I wanted to fit a minimum of 3 carboys in the fermentation chamber as well as some room for "cellaring" some bottles if I want to keep them around a while.
With the multi level I can save valuable floor space and its been working out really well having the top a few degrees cooler than the bottom. Im able to put a fresh carboy in and chill to ~64 overnight and the lower level stays ~2-3 degrees warmer which Im liking so far!