Feedback for my dual fermentation chamber build

[NoNothing]

I recently moved to TN and I don't have a basement. I miss my constant 65* MI basement wall for brewing.

Yeast are not liking fluctuating temps in the house from 70-75 in the summer and Im sure how cold we keep it in the winter cannot be great.

Solution? Fermentation chamber!

I typically will brew 2-3 beers at a time and make a day of it, so I need some space. Son of a fermentation chamber won't cut it.

Our garage is attached but non-heated. It goes from 90+ in the summer to around 40-50 in the winter. It has a window with a steel structure for an AC unit, and I happen to have a spare.

My plan is to build a 28x48" structure with 2" thick foam board insulating from the inside to ferment in. I've modeled it out and I can split it at 14" lengthwise to get 1 fermenter in one chamber and 3 in the other.

My question comes down to cooling. I plan on using a window AC unit for cooling with the thermostat bypassed and using a temp controller within the chamber itself. Might replace that with a fan and ambient air in the winter. Heat will be handled either by a pad, various keg wraps, or some reptile lamps. My plan is to have the smaller area be for lagering and the larger for ales.

If I cool directly into the lagering side with a fan exhausting into the ale side low on the wall and exhausting from ale -> lager side high will that be sufficient to keep 2 areas at different temps?

Another plan is to duct the AC separately into each chamber with a 12v relay and automotive door actuators or servo and arduino acting as control/relay opening a duct on each side so I can cool them individually or both. Both chambers would also have separate heat, no fans blowing between both of them. There's a LOT more involved in that. I already plan to 3D print the duct connection from the AC output to 3-4" PVC/ducting and then into the chamber. 3D printing some sort of duct that can be opened/closed is not impossible, but its a lot more moving parts and I'll certainly have some leakage. This version would have fans just to blow air around.

So my main question, is option 1, controlling with fans and having heat at one chamber and cool on another sufficient?

I know individual control is ideal, but then we're adding quite a bit more complication. Not to mention I need to figure out an actuated flap

 

[thekraken]

Since you're already 3d printing and using arduinos and servos why not just have the one ac unit, and one heater, and have a hot vent and a cold vent at each chamber?

 

[NoNothing]

Since you're already 3d printing and using arduinos and servos why not just have the one ac unit, and one heater, and have a hot vent and a cold vent at each chamber?

That's my main question

Will that be sufficient?

Can I reasonably keep one chamber 60-70 while the other is at 45-55 if the heating and cooling elements are in different chambers?

My concern is if I need to heat the cool chamber, that raises the temp in the hot chamber, which then needs cooling. It seems like a pretty quick way into a loop of wasting energy heating/cooling.

Or is that a non concern?

 

[thekraken]

I was thinking you'd keep the heating and cooling units outside of the cambers altogether and pipe in the hot or cold air into which ever chamber needed it.

 

[NoNothing]

I was thinking you'd keep the heating and cooling units outside of the cambers altogether and pipe in the hot or cold air into which ever chamber needed it.

Alright, I misinterpreted your response . My bad.

Thank you

That does seem ideal, just controlling each one separately.

Just seeing if anyone had any thoughts as to it being overkill.

 

[thekraken]

Just seeing if anyone had any thoughts as to it being overkill.

It might not be cost effective. I'd look into seeing how much this project would cost you in T&M vs just buying two small chest freezers from craigslist.

I use one chest freezer with a brewpi for the temperature control. One idea I've thought about but haven't needed to try out yet is to just set the chest freezer to a constant low temp like 55F, then use heat wrap on each fermenter and just use that to control the temp of each individual fermenter. I don't do lagers though, I only need to go below 60 when I'm cold crashing.

 

[NoNothing]

It might not be cost effective. I'd look into seeing how much this project would cost you in T&M vs just buying two small chest freezers from craigslist.

I use one chest freezer with a brewpi for the temperature control. One idea I've thought about but haven't needed to try out yet is to just set the chest freezer to a constant low temp like 55F, then use heat wrap on each fermenter and just use that to control the temp of each individual fermenter. I don't do lagers though, I only need to go below 60 when I'm cold crashing.

How much did all the brewpi stuff run you? I was going to use SCT-1000's for the temp control.

I figure wood and insulation is going to run around $150. Time I don't care at all, I love projects.

$40 for the controllers, lets say $40 for heat depending on how I go.

Random bits $75? ducting, filament, wiring, tape, etc.

So around $300 all together. Two chest freezers and brewpi seems like it'd run more than that.

Chest freezers that'll fit 2 fermenters are around $100-150 on CL. So I'm decently close to that.

I'll know more of exact pricing once I figure out all the parts I need, how many boards I need once I figure it all out.

I really just started this with 'Hey, I have an AC unit'

 

[thekraken]

How much did all the brewpi stuff run you? I was going to use SCT-1000's for the temp control.

I figure wood and insulation is going to run around $150. Time I don't care at all, I love projects.

$40 for the controllers, lets say $40 for heat depending on how I go.

Random bits $75? ducting, filament, wiring, tape, etc.

So around $300 all together. Two chest freezers and brewpi seems like it'd run more than that.

Chest freezers that'll fit 2 fermenters are around $100-150 on CL. So I'm decently close to that.

I'll know more of exact pricing once I figure out all the parts I need, how many boards I need once I figure it all out.

I really just started this with 'Hey, I have an AC unit'

Ahh, you already have the ac unit. Okay, that's a big help.

I picked up my used chest freezer for $80, it can probably hold 4 carboys. Though I'm about to move to fermenting in cornys, I could fit more of those in there. I actually already had everything I needed for the brewpi from other projects so it's hard for me to say. I'm guessing I could build one for around $50.

https://www.homebrewtalk.com/showthread.php?t=466106

 

[NoNothing]

Always helps what you have on hand

I need to figure out heating, I've seen tons of different things here, including hair dryers.

Chest freezers aren't super popular on craigslist, and not many large ones. One 10cf now for $150.

If I didnt want to brew beer at a decent temp that'd be a keezer

I can drive to nashville or knoxville for some better deals and more deals. Thats quite a trip. Im thinking I'll stick to the AC unit unless the price difference becomes massive.

 

[jddevinn]

You could do this the way freezer/refrigerator combos are sometimes designed. Use the evaporator from the AC to cool the cold chamber. When the hotter chamber calls for cooling use a fan to push some of the cold air from the "cold chamber" into the "hotter camber".

Remember to base the control off of the actual fermentation temp, not ambient.