Fermentation chamber build

prrriiide · Feb 2, 2011

SWMBO has given her blessing to turn "my" half of the garage into a micro brewery. I never park in there anyway.

So as a part of this, I am going to build a fermentation chamber. It's going to be a 4'hx4'dx8'w insulated plywood box with access door(s). I have a convenient window, so I am going to get a small window AC unit and duct the air in through the top of the chamber.

Now, there are a couple of ways I can go: 1) I can divide the box in half with the air inlet on one side and an AC register in the middle wall. I can adjust the register (and maybe couple it with a small fan) to allow some of the cool air into the second chamber. The side with the air inlet would be cooler for lagers and the other side for ales. OR 2) I can make it one chamber and try to find the temperature sweet spot where the lagers taste right/ferment correctly but the ales don't stall. Is 58-60 degrees too warm for lagers or too cool for ales? I want to be able to have both perking at the same time.

Beer_Guy · Feb 2, 2011

I have an Old Ale and a Pecan Brown ale fermenting at 55* right now. I used WLP007 on the Old Ale and S-05 on the Pecan. They both had nice Krausen so they should be fine.

I'd just rig up a PC fan controlled by a thermostat between the two and not be too concerned. Mount it high on the separating wall and it may be fine.

PurpleJeepXJ · Feb 2, 2011

If you want one warm side and one cool side think of this... AC removes heat so the heat has to go somewhere, normally out the back of the window unit. I had posted awhile back the idea to put the AC unit between the two chambers keeping one cool and one warm. What do you think? I never really got much of a response back the first time I suggested it.

EricT · Feb 2, 2011

PurpleJeepXJ said:
If you want one warm side and one cool side think of this... AC removes heat so the heat has to go somewhere, normally out the back of the window unit. I had posted awhile back the idea to put the AC unit between the two chambers keeping one cool and one warm. What do you think? I never really got much of a response back the first time I suggested it.

I would thing the heat form the A/C unit would be too hot for any ale. Especially in the summer.

Bensiff · Feb 2, 2011

PurpleJeepXJ said:
If you want one warm side and one cool side think of this... AC removes heat so the heat has to go somewhere, normally out the back of the window unit. I had posted awhile back the idea to put the AC unit between the two chambers keeping one cool and one warm. What do you think? I never really got much of a response back the first time I suggested it.

You would not be able to control it, if you needed heat and not cold or vice-versa you would still get both. As well, you would likely have uneven heating as the two sides are not likely to hit temp at the same time.

kanzimonson · Feb 2, 2011

Yeah, I vote for having only one chamber, and the ability to adjust it for fermenting ales or lagers. Besides, ales should only need to go in there for 5-7 days max, after which they can warm up a bit.

I was thinking through all this ferm chamber building and getting really excited, and then I got a deal on a 7 cu ft chest freezer and haven't looked back. It's just nice to be able to ferment and then crash cool in place. Plus I can use it for cold storage when it's not fermenting. I brew frequently, but not so frequently that I can't manage my space. $150 for the freezer and the controller and you're done.

Bensiff · Feb 2, 2011

prrriiide said:
SWMBO has given her blessing to turn "my" half of the garage into a micro brewery. I never park in there anyway.

So as a part of this, I am going to build a fermentation chamber. It's going to be a 4'hx4'dx8'w insulated plywood box with access door(s). I have a convenient window, so I am going to get a small window AC unit and duct the air in through the top of the chamber.

Now, there are a couple of ways I can go: 1) I can divide the box in half with the air inlet on one side and an AC register in the middle wall. I can adjust the register (and maybe couple it with a small fan) to allow some of the cool air into the second chamber. The side with the air inlet would be cooler for lagers and the other side for ales. OR 2) I can make it one chamber and try to find the temperature sweet spot where the lagers taste right/ferment correctly but the ales don't stall. Is 58-60 degrees too warm for lagers or too cool for ales? I want to be able to have both perking at the same time.

My first thought is why so tall? Are you putting in conicals? If it is a little lower it would make a great table top area for storage or working on.

I like your two chamber design, it would likely do almost exactly what you want. With temperature control you have two choices, use the chambers ambient temperature to make adjustments or use the beers temperature via a thermowell to make adjustments. In my experience the latter is superior as it eliminates temperature spikes during early fermentation and is pretty much set it and forget.

prrriiide · Feb 2, 2011

Bensiff said:
My first thought is why so tall? Are you putting in conicals? If it is a little lower it would make a great table top area for storage or working on.

I thought about that. I don't have a conical...yet. But if I build the chamber big enough to handle it, I'm ready to go when I get one. AFA the table height, I plan on using the top more for storage than for work space. I have a big old wooden desk I plan on using for that.

or use the beers temperature via a thermowell to make adjustments. In my experience the latter is superior as it eliminates temperature spikes during early fermentation and is pretty much set it and forget.

Can you explain that a little bit further? As in, I have no idea WTH you're talking about... :mug:

JohnTheBrewist · Feb 2, 2011

prrriiide said:
Can you explain that a little bit further? As in, I have no idea WTH you're talking about...

A thermowell in your fermentor allows you to put the temp controller's thermistor into the fermentor. That way, you control the temp of the beer, not the temp of the room.

prrriiide · Feb 3, 2011

Now a follow-up...

After thinking about it some more, I'm realizing that I need to build at least part of it 8' tall, due to the window placement. The AC unit will need to feed directly into the chamber for efficient cooling, yes? Ducting it won't work because the air return (which makes up most of the front of the window unit) needs to be able to draw warmer air out of the area to be cooled. So...

What I am thinking is that if I need to build part of it that tall, then I should divide it and use the top half (which will be the coolest) as a conditioning area after bottling (and eventually kegging), perhaps even as a future keg cooler/tap wall. Then use the lower half for lagering, and the short part next to it for ales. One AC unit should be plenty to cool all three sufficiently. But...

Can I depend on the physical properties of heat transfer to cool the lager chamber sufficiently (but not too much) just by letting the cold air sink through a vent in the floor of the upper chamber (especially if I don't insulate that floor in between the upper and lower chambers)? Then I can draw air from the lagering chamber into the ale chamber with a PC fan to cool it. And, if I am drawing air into the ale chamber with the PC fan, it will by default draw colder air down into the lager chamber and make it colder. Too cold, maybe? Or perhaps a duct straight in to the ale chamber from the top chamber, bypassing the lager chamber?

I did a quick sketch...

Or am I just being too complicated with wanting separate ale and lager chambers? If I kept the ambient temp at, say, 56°-58° would I be able to do ales and lagers simultaneously? Or is that too cold for an ale?

EricT · Feb 3, 2011

prrriiide said:
Now a follow-up...

After thinking about it some more, I'm realizing that I need to build at least part of it 8' tall, due to the window placement. The AC unit will need to feed directly into the chamber for efficient cooling, yes? Ducting it won't work because the air return (which makes up most of the front of the window unit) needs to be able to draw warmer air out of the area to be cooled. So...

What I am thinking is that if I need to build part of it that tall, then I should divide it and use the top half (which will be the coolest) as a conditioning area after bottling (and eventually kegging), perhaps even as a future keg cooler/tap wall. Then use the lower half for lagering, and the short part next to it for ales. One AC unit should be plenty to cool all three sufficiently. But...

Can I depend on the physical properties of heat transfer to cool the lager chamber sufficiently (but not too much) just by letting the cold air sink through a vent in the floor of the upper chamber (especially if I don't insulate that floor in between the upper and lower chambers)? Then I can draw air from the lagering chamber into the ale chamber with a PC fan to cool it. And, if I am drawing air into the ale chamber with the PC fan, it will by default draw colder air down into the lager chamber and make it colder. Too cold, maybe? Or perhaps a duct straight in to the ale chamber from the top chamber, bypassing the lager chamber?

I did a quick sketch...

Or am I just being too complicated with wanting separate ale and lager chambers? If I kept the ambient temp at, say, 56°-58° would I be able to do ales and lagers simultaneously? Or is that too cold for an ale?

56-58 is ok for some yeast but not all ale yeast, will really depend on what ale you want to make. Heres a link to the WL website that list the ale yeast and their recommended temps.
http://www.whitelabs.com/beer/homebrew_strains.html#ALE_YEAST

kanzimonson · Feb 3, 2011

You'll definitely hear stories of people fermenting ales that low, but it usually has the caveat of starting the fermentation around 62 and then once it's going you slowly lower it to the mid 50s. Then, once it slows down you have to ramp up.

I stick with my original recommendation to plan to be able to change temps anywhere from 32-80.

Beer_Guy · Feb 3, 2011

A few thoughts…

Since the cold air will fall, put a PC fan in the floor to keep the air moving around so the AC unit will read the Lager Chamber temp.

Since cold air will fall and warm air will rise you could hook up some kind of temp controlled baffle for the Ale Chamber. It might work without a baffle if you route in and out tubes from the very top and use a temp controlled PC fan. Testing would need to be done to find out.

Looks like a nice setup to me. I did a quick mod to your pic to give you a visual.

Edit: Oh, and you will need to insulate the wall between the chambers.

prrriiide · Feb 3, 2011

Beer_Guy said:
A few thoughts

Since the cold air will fall, put a PC fan in the floor to keep the air moving around so the AC unit will read the Lager Chamber temp.

Since cold air will fall and warm air will rise you could hook up some kind of temp controlled baffle for the Ale Chamber. It might work without a baffle if you route in and out tubes from the very top and use a temp controlled PC fan. Testing would need to be done to find out.

Looks like a nice setup to me. I did a quick mod to your pic to give you a visual.

Edit: Oh, and you will need to insulate the wall between the chambers.

That looks like it would work really well to keep the top and lager chambers the same temp. Do you think I could keep the top chamber colder? Like low 40s or colder for serving temp, and still be able to keep the temp up in the lager & ale chambers?

I plan to line all of the chambers with 2" pink board ans seal it with metal duct tape. I also have the option of using an in-line duct fan in the riser you added. Great idea, BTW! I might even extend that over to outlet right in front of the AC unit to try and get the warm air to go straight into the front of the window unit.

I'm going to use 2-3 of those Hong-Kong aquarium temp controllers to deal with the three chambers and try to keep the temps where I want them. Since those each have separate heat and cool controllers, I might be able to use a screw-base reptile heater to help stabilize the temps where I want them. But I'd like to minimize the electricity usage if I can. TVA keeps hiking my rates to pay for their little $750M oops down in Kingston a couple of years ago.

Beer_Guy · Feb 4, 2011

Just add a wall right in front of the AC unit. Insulate all interior walls and you got it.

Here is another quickie for you. I did a separate drawing in the lower left for the medium Temp area in case it was not easy to pick out of the full drawing.

What do you think?

Edit: Made a minor change to the drawing.

Beer_Guy · Feb 4, 2011

You will also need an access panel to the AC unit from inside the Medium Temp Area to the front of the AC for easy temp adjustment.

prrriiide · Feb 4, 2011

Wow, BG...thanks for the help!

I hadn't thought of doing it that way for the simple reason that the medium temp chamber will be my lagering chamber, and it hadn't occurred to me to want to lift a 10 gal. batch that high. But since we're only talking 3 - 31/2 feet up, it might be do-able if I split the batch into two buckets and then re-combine them before bottling/conditioning.

Also, I was thinking that down the road that the top chamber would be the perfect height for some taps and cold corny keg storage. I can insulate that floor with a few inches of batt covered by 3/4 inch polystyrene foam, or several inches of foam board. I would think that would be enough to keep the bottom chamber warm enough for lagering.

My planned construction will be 2x4 PT framing with plywood outer skin and 1.5" polystyrene inner skin with batt insulation in between. That should give me an R value better than some of houses. 2x4 wall between the two lower chambers, also with 3" batt and 1" polystyrene skin on both sides.

As I look at your original modification (post 13), it's more of what I've been thinking. Are you thinking that even with the heavy insulation that the lower chamber would stay too cold if the upper chamber were kept at 35-40*?

Beer_Guy · Feb 5, 2011

prrriiide said:
Are you thinking that even with the heavy insulation that the lower chamber would stay too cold if the upper chamber were kept at 35-40*?

If you insulate the floor between the upper and lower chambers it should do fine. We just need to rethink my drawing as for as air flow.

Since you want all three areas to be adjustable then just insulate them good on all sides, top and bottom. Set the temp in the AC chamber to just below the lowest temp and use temp controlled dampers and small PC fans to move the cold air to each area as needed.

An added thought at no charge: Maybe use some aluminum dryer vent hose for each chamber looped in, around and then out the inside of the AC chamber to keep the air from each chamber isolated. That way they would pick up the cold inside the AC chamber and yet not affect each other.

prrriiide · Apr 13, 2011

After waiting on a tax return, dealing with a family issue and several other delays, I am ready to begin construction.

I have decided to move my box to a different wall in the garage to deal with the placement of my attic stairs. So the box will be the same in concept, just the higher temp ale chamber will be on the left instead of the right.

I have acquired a 6000 BTU window unit, and have all of my lumber. I purchased some 1" bead foam board and will buy the 3-1/2" R-13 batt rolls this week. Instead of PC fans, I have elected to use bathroom exhaust fans (LINK). 50 CFM for $14 with an in-line baffle and a 3-1/2" port. I'll use 3-1/2" dryer vent for the little ducting I need. I received two of the aquarium temp controllers, and a friend gave me an analog controller that I intend to use on the coldest box.

So all I have left to buy for my parts list is the ducting, 1 fan, the batts, and some zip cord to run the electrics.

Here's the space I'll be building in:

Updates to follow...soon, hopefully!

EDIT: I just noticed that this thread is now a DIY thread...please visit this thread for updates.

Fermentation chamber build

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