3 section fermentation chamber with ebay temp controller

[barryfine]

This is my first post. I'd like to say that this forum helped me a ton when doing this project. I have one temperature controller hooked up the compressor set for cold storage of kegs and then the two other controllers are wired to power outlets for heating and cooling. I'm using computer fans to pull the cold air from the freezer to the other chambers and using space heaters for the heat.

I still have a few small details to finish, but I have the lower left chamber finished and currently have a carboy of water in it for testing prior to my brew day tomorrow.


Initial design:

Pile of supplies:

Collar built:

Frame built:

Skinned and insulated:

Top interior. Fans are attached to a temperature controller to pull cold air up from the freezer.

First test. The top right is attached to the heater and temperature controlled and the top left is attached to fans to pull cold air from the freezer.

Close up of the fans:

The three temperature controllers:

Close up of the three temperature controllers:

Detail inside the freezer. There is a fan on the bottom of the tube as well.

 

[vinper]

keep going. I want to do this with my icebox . ferment on 1 side . keep beer cold on other side

 

[barryfine]

Here is a pic of it all sealed up:

And one with my first brew in it! This is an Orange IPA using vienna, honey, and caramel malts, sweet orange peels, warrior hops for bittering, and citra and centennial for flavor and aroma.

 

[cyberbackpacker]

Looks great. I'd recommend though to raise the floor of the chamber to the left of the freezer though to minimize dead space, to allow for easier temp control (unless of course you have larger fermentation vessels than your carboy pictured). It looks like you have close to 2' of clearance above the carboy cap and your freezer is really going to need to work just to maintain that chamber, let alone the other 2 simultaneously if there is that much extra space in each.

Just my $0.02!

 

[krazydave]

Looks great. I'd recommend though to raise the floor of the chamber to the left of the freezer though to minimize dead space, to allow for easier temp control (unless of course you have larger fermentation vessels than your carboy pictured). It looks like you have close to 2' of clearance above the carboy cap and your freezer is really going to need to work just to maintain that chamber, let alone the other 2 simultaneously if there is that much extra space in each.

Just my $0.02!

Or just go buy a conical or two now, they should fit in there!

 

[T-Dan]

sweet!

 

[barryfine]

Or just go buy a conical or two now, they should fit in there!

That is the plan eventually. That shelf above the carboy is actually built to be easily removed so I can eventually make is a tall chamber with a 30 gallon plastic conical.

I did learn something today. The side of the freezer actually gets hot when it's running which was making it tough to maintain cool temps on a hot day like today. I insulated it some today and plan to add some more to it tomorrow. I also added metal tubes to the fans so that they can pull from the air at the bottom of the freezer. Will likely add fans to the bottom too for more power.

 

[barryfine]

It was 90 degrees here Monday and it exposed some weaknesses in my system that I'm working on fixing. *Monday the beer got up to 70, which isn't the end of the world, but it couldn't get it down to 67 where I wanted it. *It was only that high for a few hours though so I'm sure it's fine. *

I realized that I had placed the temperature probe for the freezer section too high so the compressor was running constantly, even though the bottom of the freezer was below freezing and I was aiming for 40 degrees in that section. *This made the outside of the freezer very hot and this heat was getting inside chamber. *I have since adjusted the temp probe so the compressor runs properly and insulated the entire chamber better. *I also added more weather stripping and tubes to the fans so that they are pulling the cold air from the bottom of the freezer section. *

I also ordered a few more fans that will be attached to the same switch at the compressor to help pull the heat away from the body of the body of the freezer in the back.

Here are some pics. *I ran out of reflective insulation so there are still a couple spots I need to patch up.

 

[jfrizzell]

What are your plans for the freezer itself and the upper area? Are you going to have kegs in the freezer with taps and they store bottles in the area above?

 

[barryfine]

What are your plans for the freezer itself and the upper area? Are you going to have kegs in the freezer with taps and they store bottles in the area above?

The freezer section will be for cold storage of kegs. I can fit two corny kegs in there and eventually plan to add taps to the side that has the temperature controllers. Since it's set to 40 degrees it would also be useful as a lagering chamber.

The top section will just be another fermentation chamber. That way I can do two different types of beer with different temperature needs. That way I can adjust to the specific temp of the carboy too instead of just for the ambient temperature.

Like I mentioned earlier, I'm planning to get a 30 gallon conical that will take up the entire left side, but it will be a few more months as I have a couple other projects I want to complete first.

 

[krazydave]

Just a thought... The skin of the freezer needs to be able to cool down, so if you wrap it up with insulation, you may be asking for problems. You may be able to just add a small air chamber between the freezer wall and your insulation though and use a fan to exhaust the heat. I would think that should be sufficient enough to get the heat away from it.

 

[krazydave]

Oh, and by the way. I don't think you need a fan on both sides of your tubes. At that rate, you're sucking the cool air out of the freezer faster than it can make it.

 

[barryfine]

Just a thought... The skin of the freezer needs to be able to cool down, so if you wrap it up with insulation, you may be asking for problems. You may be able to just add a small air chamber between the freezer wall and your insulation though and use a fan to exhaust the heat. I would think that should be sufficient enough to get the heat away from it.

Yeah, I figured that out the other day. That back has about 9 inches of space for air flow and there is about 2 inches on the side with the controllers. I'm going to add a few fans to pull out of there when the compressor is running. Would it be a good idea to have at least one fan blowing into that area as well?

I've been thinking the extra fans might be over kill too. I think the biggest issue with the left section was that the freezer skin was exposed to that chamber. Now that it is insulated there I think the fan already installed should do the trick.

 

[krazydave]

I don't think you necessarily need an input and output fan so long as there's at least someplace for air to enter if your fan is exhausting, or exit if your fan is sucking cool air in.
Ideals you should have one or the other on the top so that the heat doesn't just rise and get stuck there.

 

[barryfine]

I don't think you necessarily need an input and output fan so long as there's at least someplace for air to enter if your fan is exhausting, or exit if your fan is sucking cool air in.
Ideals you should have one or the other on the top so that the heat doesn't just rise and get stuck there.

Thanks for the advice! I'll probably get the fans wired up and installed tomorrow. I'll be sure to update the thread when it's complete.

 

[kenc_zymurgy]

It's not clear to me how those fans are set up. You want to circulate that cold air. Pull cold air from the bottom of the fridge, push it to the bottom of the chamber you wish to cool, and pull (or let it be pushed out) the warmer air from the top of the chamber you wish to cool. If you don't do it that way, you are fighting yourself.

I can't tell, but it looks like you are just pushing cold air into the chambers w/o any path for the warm air to circulate back out? Maybe I don't understand the paths there, or which way the fans are going.

-kenc

 

[barryfine]

It's not clear to me how those fans are set up. You want to circulate that cold air. Pull cold air from the bottom of the fridge, push it to the bottom of the chamber you wish to cool, and pull (or let it be pushed out) the warmer air from the top of the chamber you wish to cool. If you don't do it that way, you are fighting yourself.

I can't tell, but it looks like you are just pushing cold air into the chambers w/o any path for the warm air to circulate back out? Maybe I don't understand the paths there, or which way the fans are going.

-kenc

I appreciate your input, but my thinking is a bit different. I'm bringing cool air to the upper part of the chambers where the warmest air will be located. The cool air will then drop to the bottom and warmer air will move to the top to be cooled by the fans again. There should be air movement within each individual chamber due to natural convection. That is why the tube into the top section is not flush with the surface. I was trying to get the cool air to the top so it can cool the warm air.

I think I have it dialed it in pretty well now. I just have to wait for another really hot day to be sure.

 

[kenc_zymurgy]

I appreciate your input, but my thinking is a bit different. I'm bringing cool air to the upper part of the chambers where the warmest air will be located. The cool air will then drop to the bottom and warmer air will move to the top to be cooled by the fans again. There should be air movement within each individual chamber due to natural convection. That is why the tube into the top section is not flush with the surface. I was trying to get the cool air to the top so it can cool the warm air.

I think I have it dialed it in pretty well now. I just have to wait for another really hot day to be sure.

Well, I'm not certain it makes a lot of difference as to the cold air being injected into the bottom or the top, as the fan should get it all displaced pretty quickly anyhow. But the bigger point I was trying to make was, where is the actual circulation?

I'm just not seeing where the full cycle of air in and air out is for the chamber. Maybe I'm just missing it, but it seems like you are pushing air in - but then what? You really want a full return path - in on one end (top or bottom), out on the opposite end.

-kenc

 

[barryfine]

Well, I'm not certain it makes a lot of difference as to the cold air being injected into the bottom or the top, as the fan should get it all displaced pretty quickly anyhow. But the bigger point I was trying to make was, where is the actual circulation?

I'm just not seeing where the full cycle of air in and air out is for the chamber. Maybe I'm just missing it, but it seems like you are pushing air in - but then what? You really want a full return path - in on one end (top or bottom), out on the opposite end.

-kenc

The only circulation I have is from the natural convection of cool air falling and warm air rising. If I have issues down the road I'll consider adjusting my design, but it appears to be working so far. I've looked at a number of different fermentation chamber builds and didn't really notice anyone doing what you're talking about.

 

[kenc_zymurgy]

The only circulation I have is from the natural convection of cool air falling and warm air rising. If I have issues down the road I'll consider adjusting my design, but it appears to be working so far. I've looked at a number of different fermentation chamber builds and didn't really notice anyone doing what you're talking about.

Every one I've seen has circulation paths. They might not be obvious, but they are there.

Yes, natural convection will move the air around inside the chamber, that's not the issue. What you want to accomplish is to move the cold air from the fridge over to the chamber and return the warm air from the chamber back to the fridge. You need an in and an out path to accomplish this. It's a bit like putting your mouth on a plastic soda bottle and trying to blow into it - w/o a path for the air to escape, you don't really get any air movement. But put a hole in the other end, and the air moves right through.

It might be working because you get some initial movement and air flowing through leaks and some back through the fan once the pressures equalize. But I bet it runs out of 'gas' when it's more fully loaded, or the fridge might be called on to run too much (probably not, I just don't think you'll get enough air drawn away from the fridge).


Here's a thread with links to a classic design, the baffles, fan on one side, and port on the other provide the 'flow through' circulation.

https://www.homebrewtalk.com/f39/son-fermentation-chiller-97600/#post1067070

Here's a simple approach - remove (or reverse) one of those two fans. Then add the tubing from that fan (or hole) to go down to the bottom of the chamber. That will force air movement through the chamber and back to the fridge. I really do think your results will be rather marginal w/o full circulation. It looks like a really nice build, I'd just like to see you get the most out of it.

-kenc

 

[barryfine]

Every one I've seen has circulation paths. They might not be obvious, but they are there.

Yes, natural convection will move the air around inside the chamber, that's not the issue. What you want to accomplish is to move the cold air from the fridge over to the chamber and return the warm air from the chamber back to the fridge. You need an in and an out path to accomplish this. It's a bit like putting your mouth on a plastic soda bottle and trying to blow into it - w/o a path for the air to escape, you don't really get any air movement. But put a hole in the other end, and the air moves right through.

It might be working because you get some initial movement and air flowing through leaks and some back through the fan once the pressures equalize. But I bet it runs out of 'gas' when it's more fully loaded, or the fridge might be called on to run too much (probably not, I just don't think you'll get enough air drawn away from the fridge).


Here's a thread with links to a classic design, the baffles, fan on one side, and port on the other provide the 'flow through' circulation.

https://www.homebrewtalk.com/f39/son-fermentation-chiller-97600/#post1067070

Here's a simple approach - remove (or reverse) one of those two fans. Then add the tubing from that fan (or hole) to go down to the bottom of the chamber. That will force air movement through the chamber and back to the fridge. I really do think your results will be rather marginal w/o full circulation. It looks like a really nice build, I'd just like to see you get the most out of it.

-kenc

Thanks for the info. I'll definitely consider it. I understand you're saying about circulation, but there is one thing I don't understand, though. Why would I want to pull the air from the bottom of the chamber? That should be the coolest air in the chamber. If anything I'd think I'd want to pull the warmer air from the top out.

 

[Rundownhouse]

The only circulation I have is from the natural convection of cool air falling and warm air rising.

Why would I want to pull the air from the bottom of the chamber?

That will give you the greatest convection and cooling power. Right now you're wasting energy, because the coolest air just sits at the bottom of the freezer, never moving since warmer air (from the top) is getting pulled, pushed to the top, and then falling through relatively warmer air back to the freezer. That's a bit of a simplification/exaggeration, but it seems pretty intuitive that to get the fullest flow of air, you want the stuff at the bottom of the freezer to get pulled to the top of the chamber.

 

[barryfine]

That will give you the greatest convection and cooling power. Right now you're wasting energy, because the coolest air just sits at the bottom of the freezer, never moving since warmer air (from the top) is getting pulled, pushed to the top, and then falling through relatively warmer air back to the freezer. That's a bit of a simplification/exaggeration, but it seems pretty intuitive that to get the fullest flow of air, you want the stuff at the bottom of the freezer to get pulled to the top of the chamber.

I understand pulling the cold air to the top of the chamber, but he's suggesting pulling out the cold air from the bottom and putting it back into the freezer section. That sounds counter intuitive to me.

 

[krazydave]

What he's suggesting is that you need a path for air to flow. When you push air into a chamber, you need somewhere for that air to go, or or it's like putting air in a tire. You're just creating air pressure which is most likely just pushing your cold air out of every crack that it can find. Convection alone is almost non-existent in your chambers unless your fans aren't running, also. The fans mix everything up quite well on their own, so nothing is really settling.

Ideally, you want to be able to push cold air in while giving a path for the warmer air to go back to the freezer to re-chill.

 

[barryfine]

What he's suggesting is that you need a path for air to flow. When you push air into a chamber, you need somewhere for that air to go, or or it's like putting air in a tire. You're just creating air pressure which is most likely just pushing your cold air out of every crack that it can find. Convection alone is almost non-existent in your chambers unless your fans aren't running, also. The fans mix everything up quite well on their own, so nothing is really settling.

Ideally, you want to be able to push cold air in while giving a path for the warmer air to go back to the freezer to re-chill.

Yeah, I understand that, I was just confused why he thought I should I remove the air from the bottom of the chamber instead of from the top. I could easily just change the direction of one of the fans for the left section to get the kind of air flow you're talking about. His suggestion would require me to add a tube the left the section which would take up valuable real estate.

 

[krazydave]

If both of your fans in the left section are blowing cold air in. I would definitely change the direction of one of them. You may also want to consider adding a tube on the freezer side of the fan blowing in the chamber that goes to the bottom of the freezer and sucks the cold air from there and see if that performs any better also.

As for the tube in the left section, you could probably do without it since the fan blowing in there is going to be enough to stir up any stratification that may exist.

 

[barryfine]

If both of your fans in the left section are blowing cold air in. I would definitely change the direction of one of them. You may also want to consider adding a tube on the freezer side of the fan blowing in the chamber that goes to the bottom of the freezer and sucks the cold air from there and see if that performs any better also.

As for the tube in the left section, you could probably do without it since the fan blowing in there is going to be enough to stir up any stratification that may exist.

I already have tubes attached to the fans on the freezer section for both of those fans. I added those earlier this week and it really helped a lot.

 

[krazydave]

I would just turn a fan around then, and take the tube off the freezer side of the one you turn around.
That should cool that chamber down a lot faster and make the whole system more efficient.

 

[barryfine]

I would just turn a fan around then, and take the tube off the freezer side of the one you turn around.
That should cool that chamber down a lot faster and make the whole system more efficient.

That's the kind of fix I like. Nice and easy. Unfortunately, trying to add circulation to the top chamber may prove to be more difficult. It would also take up space that I really don't want to give up. I think I'm going to see how it performs on a really hot day before I make any changes to the top chamber.

 

[krazydave]

for the top chamber, you could try just putting another hole over your freezer. It's not ideal since the cold air will essentially settle and fall through it once the fan stops running. For this reason you probably wouldn't want it much bigger that your fan hole either. But it should work.

The real test will not only be a hot day, but when you have multiple beers in there bubbling away in primary fermentation. Those tend to heat up a chamber more than you'd think!