My semi walkin 5000 btu fermentation chamber

oldstyle69 said:

TARDIS for the win. very nice build. i just made one out of an old dresser.

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I also saw a guy build a keezer out of an old entertainment cabinet that was used to house a CRT TV (not flat screen), and stereo equipment...maybe it once even held a beta VCR :rockin:

First batch is fermenting away.

Interesting build. While it was smart introducing the cold "heavier" air at the top, what kind of temperature fluctuation are you getting from the top to the bottom half? Cause even when I reach into my keezer (which is only half that height) I can feel a tremendous difference from the top to the bottom. Obviously you're not getting much air circulation past your solid fiber board shelf. Is there a reason you went with a stacking design, as opposed to making a side-by-side design? I plan to go with a single level design when I make one.

I chose a stacked design to replicate the fridge I was using. I like to use gravity whoever possible, so I can just drain the fermenter to the kegs. The shelf is solid side to side, but it has several inches of clearance in the front and back. Before I installed the 1" foam on the inside of the door I could sit on the shelf with my legs hanging down and close the door. I'll get a couple thermometers and water bottles and see what kind of liquid temp gradient I have.

Very nice. I would just cover the shelf with contact paper for easy cleanup and reduce mold growth.

That's a good idea. I hadn't crossed that bridge yet.

I assume that is a 15g conical. Are you pumping wort into it or lifting it up to the shelf?

I have a chugger pump now, so I'm pumping it. Before, I was draining the kettle into my bottling bucket, and sitting it on top of the fridge to drain into it. Real PITA.

I keep thinking about a conical or two. I would also have to use my pump for the transfer.

Great ideas and nice build. Not trying to be a kill-joy, but wouldn't an old fridge off Craigslist be much cheaper, get much colder, and be much more economical to run? I mean, I can see using this for fermentations to keep the temps where they need to be such as for bock style beers, (Never tried to see if you can turn a fridge temp up high enough to hold at high 50's to low 60's) but for actual cold crashing, an old fridge is hard to beat.

Also, the idea about computer fans is a good one. They use very very little electricity, are usually very quiet, and are cheap. I use them in egg incubators to keep all the air in the enclosed space circulating and the same temp. Still air will settle out fairly quickly.. hot to the top and cold down.

Also, you don't want the A/C blowing directly on your bucket since it's much colder than the surrounding air. Whatever surface it hits, it'll make a cold spot. Your wort on the A/C side of your bucket will get much colder than the oposite side. Kind of like in your car with the A/C going and a vent blowing directly on you.. eventually that spot will feel like it's frezing even though the surrounding air and the rest of you is much warmer.

Just my 2 cents.. if it's worth even that.

Very nice build. I'm starting to put some ideas together to build a nice chamber. It's time to upgrade from my son of a fermentation chamber which can only hold one carboy.

trbig said:

Great ideas and nice build. Not trying to be a kill-joy, but wouldn't an old fridge off Craigslist be much cheaper, get much colder, and be much more economical to run? I mean, I can see using this for fermentations to keep the temps where they need to be such as for bock style beers, (Never tried to see if you can turn a fridge temp up high enough to hold at high 50's to low 60's) but for actual cold crashing, an old fridge is hard to beat.

Also, the idea about computer fans is a good one. They use very very little electricity, are usually very quiet, and are cheap. I use them in egg incubators to keep all the air in the enclosed space circulating and the same temp. Still air will settle out fairly quickly.. hot to the top and cold down.

Also, you don't want the A/C blowing directly on your bucket since it's much colder than the surrounding air. Whatever surface it hits, it'll make a cold spot. Your wort on the A/C side of your bucket will get much colder than the oposite side. Kind of like in your car with the A/C going and a vent blowing directly on you.. eventually that spot will feel like it's frezing even though the surrounding air and the rest of you is much warmer.

Just my 2 cents.. if it's worth even that.

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Sure, you cold buy an old fridge off CL. But, it would be smaller and could only hold one fermenter at a time...maybe two. It's also old. Every used freezer I ever bought did not last and those were from the so called repair shops that buy and sell them. Then I was left with the carcass and had to pay someone to haul it away. An old fridge has even more potential problems. That being said, I do have our old GE fridge from a previous home in our garage. I use it for crash cooling. It will only hold one of my 13gal fermenters at a time.

This particular build was built as an upright. I built mine as a cube and I can get 7 fermenters inside. I have taken mine down to 50F with no problem and I use a very similar A/C unit as the OP of this thread. Since this type of system could freeze up, I have not tried colder on mine.

trbig said:

Great ideas and nice build. Not trying to be a kill-joy, but wouldn't an old fridge off Craigslist be much cheaper, get much colder, and be much more economical to run? I mean, I can see using this for fermentations to keep the temps where they need to be such as for bock style beers, (Never tried to see if you can turn a fridge temp up high enough to hold at high 50's to low 60's) but for actual cold crashing, an old fridge is hard to beat.

Also, the idea about computer fans is a good one. They use very very little electricity, are usually very quiet, and are cheap. I use them in egg incubators to keep all the air in the enclosed space circulating and the same temp. Still air will settle out fairly quickly.. hot to the top and cold down.

Also, you don't want the A/C blowing directly on your bucket since it's much colder than the surrounding air. Whatever surface it hits, it'll make a cold spot. Your wort on the A/C side of your bucket will get much colder than the oposite side. Kind of like in your car with the A/C going and a vent blowing directly on you.. eventually that spot will feel like it's frezing even though the surrounding air and the rest of you is much warmer.

Just my 2 cents.. if it's worth even that.

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I built this unit because I had an old fridge that lasted a year. If this lasts 4 years I've come out ahead, and I only have to replace the A/C then, not retrofit an entire fridge.

I'm still in the learning phase as far as air stratification goes. I'll address that issue when I have more data.

I've been thinking about putting a deflector in to blow the air over the fermenter so it's not blowing directly on it. For now the built in deflector helps divert the air flow some. I liked the build I saw with the A/C on top of the chamber with ducts blowing down, but I didn't want to build all that duct work.

trbig said:

Great ideas and nice build. Not trying to be a kill-joy, but wouldn't an old fridge off Craigslist be much cheaper, get much colder, and be much more economical to run? I mean, I can see using this for fermentations to keep the temps where they need to be such as for bock style beers, (Never tried to see if you can turn a fridge temp up high enough to hold at high 50's to low 60's) but for actual cold crashing, an old fridge is hard to beat.

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+1 on the space dealie. Much more room in a self built setup, and you don't have to worry about voiding the warranty.

One thing I'm running into now is it has a tendency to freeze up if I go below 60. I've got two on delay relays on the way to basically make a defrost cycle. Cost $10. Still cheaper than a different controller. I actually haven't seen a controller that has a feature like that. The stc1000 has a compressor surge protection circuit, but nothing to keep it from running for hours on end. I may also add a couple computer fans.

That is sweet!

brewguyver said:

+1 on the space dealie. Much more room in a self built setup, and you don't have to worry about voiding the warranty.

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All the room in the world won't help you if you can't get it down to cold crashing temps. And if you ever find an old fridge on Craigslist that's still under warranty, let us know, will ya?

n240sxguy said:

One thing I'm running into now is it has a tendency to freeze up if I go below 60. I've got two on delay relays on the way to basically make a defrost cycle. Cost $10. Still cheaper than a different controller. I actually haven't seen a controller that has a feature like that. The stc1000 has a compressor surge protection circuit, but nothing to keep it from running for hours on end. I may also add a couple computer fans.

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I believe some of the watlow PID controllers can take multiple probe inputs and have all sorts of wait and rest cycles, auto leveling, etc. If you're already putting in your own relays then it might be worth looking at - one probe could go on the fins and trim it down if they're freezing up, or it could do rest cycles. My buddy has a few that were pulled out of a unit for managing tissue samples etc (e.g. Very accurate). I'll find out what the model number is.

trbig said:

All the room in the world won't help you if you can't get it down to cold crashing temps. And if you ever find an old fridge on Craigslist that's still under warranty, let us know, will ya?

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Heh - can't cold crash one fermenter without cold crashing all of them (without a bunch of extra engineering). Can always buy the fridge later and use it just for that, and keep the pipeline moving using this one!

brewguyver said:

I believe some of the watlow PID controllers can take multiple probe inputs and have all sorts of wait and rest cycles, auto leveling, etc. If you're already putting in your own relays then it might be worth looking at - one probe could go on the fins and trim it down if they're freezing up, or it could do rest cycles.

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I already ordered my relays unfortunately. I'm trying to get them "unshipped" right now. If that works I plan to get an STC-1000 and use it to monitor the fin temp. I wish I had though of doing that yesterday instead of trying to build a defrost circuit into it. I was planning on doing that and computer fans, but I would rather do the extra controller.

n240sxguy said:

I already ordered my relays unfortunately. I'm trying to get them "unshipped" right now. If that works I plan to get an STC-1000 and use it to monitor the fin temp. I wish I had though of doing that yesterday instead of trying to build a defrost circuit into it. I was planning on doing that and computer fans, but I would rather do the extra controller.

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It's probably much simpler that way - seems like live got the right approach.

Lots simpler. I will only have to make or break one contact then.

I always keep a spare STC-1000. For the $19 Amazon price, it made sense for me to buy spares. I even found a guy on ebay selling extra probes and these have metal tips instead of plastic. I have two of those, but have not tried them yet.

As far as crash cooling, I use our garage fridge for that. My wife allows me a little space in there for that. When I built my fermentation cabinet, I originally planned a wall inside splitting it in half. I have double doors so it would work. One side would be cold crash or lager temp and the other side for ales. I was going to use two STC-100s. One would control the A/C on the coldest side and the other would control a bilge blower that would be mounted to the separating wall which would turn on and blow cool air into the ale side when needed. The separating wall would be two pieces of plywood or OSB or something similar sandwiching a piece of foam. My only fear is that this may overwork the A/C unit. I would also lose fermentation capacity. It holds 6 fermenters now, but I will probably never have that many going at once.

The same could be done for yours, just in a vertical layout instead of horizontal. You could use one door or change it to two.

My layout:

limulus said:

I always keep a spare STC-1000. For the $19 Amazon price, it made sense for me to buy spares. I even found a guy on ebay selling extra probes and these have metal tips instead of plastic. I have two of those, but have not tried them yet.

As far as crash cooling, I use our garage fridge for that. My wife allows me a little space in there for that. When I built my fermentation cabinet, I originally planned a wall inside splitting it in half. I have double doors so it would work. One side would be cold crash or lager temp and the other side for ales. I was going to use two STC-100s. One would control the A/C on the coldest side and the other would control a bilge blower that would be mounted to the separating wall which would turn on and blow cool air into the ale side when needed. The separating wall would be two pieces of plywood or OSB or something similar sandwiching a piece of foam. My only fear is that this may overwork the A/C unit. I would also lose fermentation capacity. It holds 6 fermenters now, but I will probably never have that many going at once.

The same could be done for yours, just in a vertical layout instead of horizontal. You could use one door or change it to two.

My layout:

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I don't think it would overwork the A/C to do that. The volume to be cooled would be half what you have now. I have a keezer I can put carboys in to lager if the need ever arises. I would like to make a bock eventually. I should probably try a real one first to make sure I like it as much as the more commercial ones I've tried. Not sure if there is a difference. I just bought a STC-1000 for $17.99 on amazon. Every time I buy a controller it's less. I paid around $30 for the one on my chamber, $22 for my keezer, now this one is even less. Free prime 2 day shipping to boot. You find all sizes of thermocouples on Amazon cheap too. I paid $6 for the one in my chamber. It's 4" stainless.

trbig said:

All the room in the world won't help you if you can't get it down to cold crashing temps. And if you ever find an old fridge on Craigslist that's still under warranty, let us know, will ya?

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Cold crashing is nice, but totally no necessary, and pretty pointless if you are kegging.

bleme said:

Cold crashing is nice, but totally no necessary, and pretty pointless if you are kegging.

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He was the one saying he wanted it to get to the 30's. I just guessed that was why. Plus, cold crashing sure helps to clear things up and get settled out BEFORE kegging or bottling. (Or getting rid of the "rhino farts" in ciders) You don't think it's necessary, some think it's critical for the final product. So who's right?

trbig said:

He was the one saying he wanted it to get to the 30's. I just guessed that was why. Plus, cold crashing sure helps to clear things up and get settled out BEFORE kegging or bottling. (Or getting rid of the "rhino farts" in ciders) You don't think it's necessary, some think it's critical for the final product. So who's right?

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I don't know that I've ever successfully done a cold crash, or know that what I did had any effect. I dropped the temp in my old fridge for the last batch before it died, but I wouldn't swear it did any good. It was the only one I've kegged without filtering, and it was pretty clear. Just want to have the capability to do so if I want.

I keg almost all my beer and I also cold crash every batch before kegging. It really clarifies the final product. The only beer I have not cold crashed in the last two years was a bottle conditioned barleywine that has been excellent and will be brewed again this year. However, this year, I'm going to keg 2.5 gallons and bottle the rest.

trbig said:

He was the one saying he wanted it to get to the 30's. I just guessed that was why. Plus, cold crashing sure helps to clear things up and get settled out BEFORE kegging or bottling. (Or getting rid of the "rhino farts" in ciders) You don't think it's necessary, some think it's critical for the final product. So who's right?

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The guy who is right is the one making the beer that he drinks. Putting down the OP because he didn't go with a fridge to suit YOUR process is downright rude.

Alright, here's the update. I got my relay order cancelled, my STC-1000 ordered, and in the meantime discovered that if I back my A/C off of the max setting, it doesn't seem to freeze up. I think 7 is the highest setting. I backed it off to around 3. Came back an hour later and it was getting warmer. Turned it to 4. Came back an hour later. Still getting warmer. Turn it to 5. Come back an hour later, and it's sitting comfortably back at 62 with the A/C off. I set it to 61 a few minutes ago. I'll see how it's doing in the morning.

bleme said:

The guy who is right is the one making the beer that he drinks. Putting down the OP because he didn't go with a fridge to suit YOUR process is downright rude.

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LOL.. Could you please post where I've put anyone down? Asking questions about something and why they did something is putting someone down? My point was exactly as yours is. Whoever is doing the making and drinking is correct.. meaning they are both right. You don't think cold crashing is absolutely necessary. Fine and good. Works for you, right? So should I be offended by you inadvertantly putting others down if they do? Isn't it rude to assume the way YOU brew should be good for all and that everyone should deem cold crashing unneeded as you do? Is it rude to simply think otherwise or state something that has worked for them? Others think it's absolutely necessary. Fine for them, right? *Insert smiley face again?*

As I stated, I thought he was wanting this chamber to get into the 30's so he could cold crash in there, so I asked why he didn't just get a fridge for that, which was answered. Then you go off topic to state your opinion and say that cold crashing isn't even needed, but I'm the rude one if I state anyone else's opinion if it's contrary. Mmkay. Got it.

To anyone finding my posts rude, I truly apologize. I thought the LOL's and smilies would be an indication of my intent, but things get lost in writing. Again, I'm sorry, and I'll refrain from any further posts here to avoid confusion. Cheers, and good drinking to you all.

trbig said:

LOL.. Could you please post where I've put anyone down? Asking questions about something and why they did something is putting someone down?

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I took the tone of your post to be condescending. After quickly reading several of your other posts on other threads, I see that isn't your MO and I'm sorry for the misunderstanding.

It can be quite frustrating to be a pioneer on this forum. There are always people putting you down for not brewing the same way they do. I can get a bit touchy.

n240sxguy said:

I opted to put an off delay relay on the A/C's internal fan to run it after the temp controller turns off the compressor. I figure running it for a couple minutes would move more air than a computer fan running constantly. By the time any temp stratification occurs the A/C will probably be kicked back on. That's all speculation at this point. I'm gonna try to measure some temps in the next few days.

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I built a nearly identical ferm chamber with an a/c unit, but ended up just switching the outlet with an SSR, and shorting the thermocouple to keep it running below 50. It works fine, and definitely can cool below 35, but the coils do appear to freeze. I suspect this is happening because the whole unit is shutting down and there is no air movement. How did you bypass the compressor and fan separately? Is this obvious from the wiring inside? Maybe a constantly running computer fan would solve my problem. . .

PLOVE said:

I built a nearly identical ferm chamber with an a/c unit, but ended up just switching the outlet with an SSR, and shorting the thermocouple to keep it running below 50. It works fine, and definitely can cool below 35, but the coils do appear to freeze. I suspect this is happening because the whole unit is shutting down and there is no air movement. How did you bypass the compressor and fan separately? Is this obvious from the wiring inside? Maybe a constantly running computer fan would solve my problem. . .

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I would say yours is freezing before it shuts down. The fan keeps pulling moisture across the coils while its running; making a big block of ice. That's what I've been running into. I switch the outlet to power the A/C like you do. I spliced into the high speed wire for the fan, ran it to be the trigger for the off delay relay, ran a hot wire to the input of the relay, and ran a wire back to the other side of where I spliced into the fan wire to provide the power for the fan. A little difficult to see what I did in these pics, but maybe.
















The wire I spliced is coming out of the high/low/ high cool/low cool switch. The piece of extension cord hanging above the outlet is the wire to the relay and back. The piece of cord going to the outlet is the power for the always on outlet. I broke the little tab on the side of the outlet so I could switch one. The single black wire is the switched power for the A/C.

As far as computer fans go, I'm kinda on the fence. I'm thinking about getting a couple, but not sure where I should put them. I'm gonna take the cover off the A/C so I can have maximum airflow over the coils. I've thought about putting them in front of the coils. My concerns were which way to face them. Blowing toward the coils may keep them from frosting up. Blowing away would keep air circulating, but would fight the A/C fan. I think my best option would be to mount them on the back side of the shelf blowing down. I'm also thinking about adding a deflector to flow the air over my fermenter so it's not blowing right on it. I have the louvers turned toward the upper back, but some air still hits the fermenter directly. May not be a big issue though.

I know this won't help you or anyone right now, but maybe next year this will be a helpful Temp Controller!

https://www.homebrewtalk.com/f163/new-temperature-controller-brewbit-417306/

That is very cool. I would love to have something like that. I could never make myself pay for it though. Guess I'm stuck in the old ages of just going and looking at my chamber to adjust it.

Just a suggestion, if you end up having a problem with drastically different temps from top to bottom, you could use a computer fan at the bottom, connected to a piece of PVC (3 or 4") as ducting to pump the cold air up to the top of the chamber.

Yretsof said:

Just a suggestion, if you end up having a problem with drastically different temps from top to bottom, you could use a computer fan at the bottom, connected to a piece of PVC (3 or 4") as ducting to pump the cold air up to the top of the chamber.

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I will take that under advisement. I've been pondering the fan setup I want to use.

Yretsof said:

Just a suggestion, if you end up having a problem with drastically different temps from top to bottom, you could use a computer fan at the bottom, connected to a piece of PVC (3 or 4") as ducting to pump the cold air up to the top of the chamber.

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That is what I did in my coffin keezer.

n240sxguy said:

I would say yours is freezing before it shuts down. The fan keeps pulling moisture across the coils while its running; making a big block of ice.

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Appreciate the thoughtful response and pics. So, in your estimation is running the fan after the compressor turns-off effectively "melting" any ice build-up off of the coils? I'm starting to see why you had made a comment about tilting the A/C unit to drain water. In my system I'm using a BCS to monitor temps (wort and air), and turn on heat (lightbulb) and cooling (A/C) as needed. This perhaps gives me two options: (1) by pass fan and run continually. Only turn on/off compressor. Or (2), bite the bullet, by another SSR and independently control fan and compressor. I can regulate timing easily enough on the software side.

Guess I have a little more thinking to do. Fortunately, I'm currently only fermenting ales in the mid-60's. A/C comes on occasionally, but the insulation and placement of my fermenter in the garage minimizes need for cooling.

Thanks again. . .
P

PLOVE said:

Appreciate the thoughtful response and pics. So, in your estimation is running the fan after the compressor turns-off effectively "melting" any ice build-up off of the coils? I'm starting to see why you had made a comment about tilting the A/C unit to drain water. In my system I'm using a BCS to monitor temps (wort and air), and turn on heat (lightbulb) and cooling (A/C) as needed. This perhaps gives me two options: (1) by pass fan and run continually. Only turn on/off compressor. Or (2), bite the bullet, by another SSR and independently control fan and compressor. I can regulate timing easily enough on the software side.

Guess I have a little more thinking to do. Fortunately, I'm currently only fermenting ales in the mid-60's. A/C comes on occasionally, but the insulation and placement of my fermenter in the garage minimizes need for cooling.

Thanks again. . .
P

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I figured using the internal fan would give you the maximum cooling from the coils after the compressor kicked off. As long as the coils don't actually freeze solid, it should defrost them.

You could control the fan with a cheap ice cube relay. No need for a solid state unless you find them cheap.