Outdoor Fermentation chamber

Hey Yall,
Brewing in the south, you really need to have something to be able to ferment in the summer. Everything I've used has had some sort of drawback , but I have high confidence with my latest solution.

Basically, it's an outdoor fermentation chamber that uses a small 5K BTU LG window air conditioner. (in the winter , a simple ceramic space heater) controlled by a dual-relay STC-1000.

I tape the thermocouple to the side of the fermenter covered with a couple layers of reflectix insulation so that it measures the wort instead of the air temp.

In the first pic, it's still in the construction phase, and i'm just testing the fit of one of the fermenters, you can see the AC unit in the back wall.

the 2x4 walls have R15 insulation, the roof has R20, and the floor and door use R15 rigid foam insulation. All seams and joints are caulked to minimize outside air and moisture entry. The door is sealed with 1.5" wide x 3/16" thick foam weatherstrip.

pretty fricken awesome man, any reason you didnt go bigger?

Grod1 said:

pretty fricken awesome man, any reason you didnt go bigger?

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Thanks Grod1, the reason I didn’t go bigger is I really need to be able to move it on occasion. I could’ve put it on casters, but that would’ve made it more difficult to get a full fermenter in and out.

Plus, the bigger you go, the more electricity you use. Great job!

That's pretty danged sweet. Got me thinking!

How cold can that AC unit get it? Have you tested? I'd wondering about cold crashing to low 30's. Also, if you have a kill-a-watt, put it on the supply to the AC and let it go for a while. Interested to know how much energy to keep it at fermenting temps for a while.

passedpawn said:

How cold can that AC unit get it? Have you tested? I'd wondering about cold crashing to low 30's. Also, if you have a kill-a-watt, put it on the supply to the AC and let it go for a while. Interested to know how much energy to keep it at fermenting temps for a while.

Click to expand...

the AC unit has it's thermocouple "hijacked" with a heating device (switched on by the STC1000) so that the compressor will stay on and run the temp down to 35 degrees, if set to that temp. Same sort of principle that the Coolbot uses.

I haven't measured the power consumption , but the insulation should keep the cool inside and the heat outside.

Looks awesome and a great solution for getting it near an outdoor brew space.

Just one concern, I don't think the stc-1000 has a waterproof front panel. It looks like it is partially protected by the eaves, but storms and fog could get in there and short out the controller. You might try a 2-gang outdoor electrical cover. Something clear and low profile like this might help protect the investment and work.

That's awesome! Ive been debating on what to do with my setup. Im now in the garage next to my mower and critters. Ive got glycol chilled conicals but might scrap that and build a cold room. Or just upgrade to the new pressure rated unitanks, keep everything under a few pounds so I dont have to worry about fumes. Been trying to decide for a couple weeks.

SleepyCreekBrews said:

Hey Yall,
Brewing in the south, you really need to have something to be able to ferment in the summer. Everything I've used has had some sort of drawback , but I have high confidence with my latest solution.

Basically, it's an outdoor fermentation chamber that uses a small 5K BTU LG window air conditioner. (in the winter , a simple ceramic space heater) controlled by a dual-relay STC-1000.

I tape the thermocouple to the side of the fermenter covered with a couple layers of reflectix insulation so that it measures the wort instead of the air temp.

In the first pic, it's still in the construction phase, and i'm just testing the fit of one of the fermenters, you can see the AC unit in the back wall.

the 2x4 walls have R15 insulation, the roof has R20, and the floor and door use R15 rigid foam insulation. All seams and joints are caulked to minimize outside air and moisture entry. The door is sealed with 1.5" wide x 3/16" thick foam weatherstrip.

Click to expand...

Very nice! What do you estimate it cost you to make it? Just asking to see how it compares to the chest freezer + collar + stc 1k setup I use which was $300 (new freezer) + $15 + $35 = $350.

beernutz said:

Very nice! What do you estimate it cost you to make it? Just asking to see how it compares to the chest freezer + collar + stc 1k setup I use which was $300 (new freezer) + $15 + $35 = $350.

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Thanks.
Cost is pretty comparable I was initially shooting for $250, but as usual, there were some cost over-runs
What i've noticed in the past week is that it doesn't run much .

SleepyCreekBrews said:

the AC unit has it's thermocouple "hijacked" with a heating device (switched on by the STC1000) so that the compressor will stay on and run the temp down to 35 degrees, if set to that temp. Same sort of principle that the Coolbot uses.

I haven't measured the power consumption , but the insulation should keep the cool inside and the heat outside.

Click to expand...

Just came across this thread and wanted to say thanks, awesome build and idea (I am pretty sick of carrying 12 g in sankes up and down stairs, to be honest...well, to be really honest, I was pretty sick of it back then).

My mind immediately went to the coolbot, as I have one. Then I saw your post here. I used it to control a 120 sf cheese cave (couple of pics in another thread), with a way-overkill ac, but at least I've still got both for that monster ... room down the road. I don't have much experience at all with digital controls, but I have built a couple pid units for my smaller cheese vats. So this is really impressive and inspirational. Thing of beauty!

Ive seen the Coolbots used in some of the small craft breweries here in the Raleigh area, they work well. That's what gave me the idea.

Over the winter, I usually do a lager, and this past winter the Feb temps were in the 70s, so I was using the same AC unit and control to hold the garage at 50 degrees.

Props on the build...came out nice.
Curious, Do you have no room for a chest freezer or upright fridge
I'm wondering what the electric bill will be on a 88 deg 2 week run in the summer
Sounds like a ton of insulation though
My electric cost is stupid expensive... 18 cents a KWH...that would be a tough sell telling the wife I need to cool my beer with an air conditioner

Heck while you were at it you should have just moved your entire brewing operations out side! Build 6 of them as one! and your got a nice little brew shed! I've been wanting out of my garage for years but I can't afford the electrical run.

JONNYROTTEN said:

Props on the build...came out nice.
Curious, Do you have no room for a chest freezer or upright fridge
I'm wondering what the electric bill will be on a 88 deg 2 week run in the summer
Sounds like a ton of insulation though
My electric cost is stupid expensive... 18 cents a KWH...that would be a tough sell telling the wife I need to cool my beer with an air conditioner

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Thanks Johnny,
Honestly, there's already enough $hit in the garage that I didn't want another fridge/freezer (see below) . Also , 10-15 gallon fermenters are too heavy to try and lift, so that's one of the other contributing factors that motivated me to do this.
It seems so far, that it only runs for 5-10 minutes/hour so I don't see it impacting the electric bill too much, the insulation seems to be working well. (our power is 9 cents here).

LarMoeCur said:

Heck while you were at it you should have just moved your entire brewing operations out side! Build 6 of them as one! and your got a nice little brew shed! I've been wanting out of my garage for years but I can't afford the electrical run.

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Brewing in the garage is pretty comfy at the moment.

I've been eyeballing one of these for my brewery for years. The cost to run power to it is more then the building itself.

That's a lot of stainless to be trusting to a tiny hasp and lock. I hope you know your neighbors well. Otherwise, great idea and build. Like the others, this has got me thinking...

LarMoeCur said:

I've been eyeballing one of these for my brewery for years. The cost to run power to it is more then the building itself.

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that's nice looking LMC !
Cant you just trench a couple circuits over to the site from the house panel? Hell, a single 50 amp would prolly suffice. DIY-style?

Sleepy,

Unfortunately or fortunately depending how you look at it. I have a 50 amp electric system. So, with my fermentation chamber, air conditioning, TV, lights, sound system, you know all the stuff for a great man cave. I need at least a 200 amp circuit. The cost of the power run is ridiculous!

Sweet chamber setup man! Also awesome garage & Jeep!