Fermentation/storage/serving cabinet critique

I'm planning on building this ferm chamber soon and wanted some input on things that might not work so well and what could be improved on it.



I'll have 3 sets of doors on the front, one for each: bottles, serving keg, and primary keg. The construction isnt such an issue; i feel secure with my building skills. it's just wood and foamboard 2" insulation.

Some things i'm concerned with:
1. do you think the bottles and grain/yeast, etc. will prevent cold air from circulating to the keg areas?
2. should i have a 2nd fan in the removable divider? One for cold into designated ferm chamber, one to pump the warmer air out (and back into the main compartment)?
3. Should i put a fan into the minifridge, attached to any temp control that i install so that when the fridge compressor kicks on, so does the fan, circulating the air?

Thanks.

Wow, I've been planning something almost identical and had some of the same questions, so thanks for posting this. I don't have any helpful advice, but I'm curious to see what people say about how much volume a mini fridge can happily cool.

Just based on the drawing, though, don't forget you've also got the volume of the fridge to put things in. For some reason I discounted that for the first few drawings...

i considered that. the fridge is this one: http://products.geappliances.com/ApplProducts/Dispatcher?REQUEST=SpecPage&Sku=GMR04HASCS

i bent the coolant part/freezer component down against the rear wall and have moved the temp control (soon to be replaced by love or johnson control) and can fit a carboy in there. i thought i'd leave that part unoccupied for the few times i might want to try a lager in 5 gallon batch, as experimentals instead of ending up with 10g of beer i'm not fond of. And i thought i'd make the bottle storage shelves removable so that if necessary i could just put another keg in that area after emptying out the bottles

I'm no thermal expert but here's my thoughts...
1.The stuff in the first compartment won't interfere with the cooling of the other compartments in fact, the more stuff you have in the cooler the greater your thermal mass so temps should be more stable.
2.You don't need a 2nd fan normal presure equalization will take care of that, but I would put a hole about the size of the fan at the bottom of the barrier to let cold air into the fermentation compartment and use the fan to suck the warm air out of the top of the fermentation compartment. Did I explain that well?? Turn the fan around so it is pulling relatively warm air out of the top of the fermentation side and the hole at the bottom of the wall would let cold air in from the lager/serving side.
3. I would think you would want a fan blowing across the cooling element in the fridge to make sure it doesn't ice up.

that all makes sense.
#3, when do you think i should set that fan to turn on? when the compressor kicks in, or more often? if more often, how should it be set? maybe with a timer, once an hour for a minute, every 6 hours for a few minutes, ...?

I would put the fan on all the time. It won't cool much. Just enough. +1 the fan on the coils. Remember you are trying to use a cooling element designed to cool 2.4 ft3 and now trying to cool double that. Keep an eye on the coils on the back of the fridge. They may tend to freeze up.

Ideally the fan on the cooling element would go on when the element goes on but stay on for a few minutes after the element goes off - sort of like the fan on your furnace stays on for a few minutes after the furnace shuts off to get all the heat out of your ducts and into the house.

i think with the fan I have 3 options: 1. a time delay 2. on while, and only while, the compressor is on 3. on all the time.

which might be best then? it seems like 2 and 3 are better options, 2 maybe the best. if anyone knows how to set it up any other way, i'm all ears.

thanks for the ideas

I would go with 3. Ideally you want the fan doing most of its work while the compressor is off. This gives the fan the best opportunity to defrost the coils.

New-B-Brewer said:

1.The stuff in the first compartment won't interfere with the cooling of the other compartments in fact, the more stuff you have in the cooler the greater your thermal mass so temps should be more stable.

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Does this imply that, if there's room, I should store unused kegs & carboys full of water (or dilute bleach-water) in the chamber?

I mean, brewing more is obviously a better answer, but short of that?

Computer fans are REALLY cheap, and meant to run a lot. I'd keep the one pointed at the coils on all the time. If it dies out, just replace it with a new one (cost ~ $5). I have three computer fans in my keezer that run at all times. They don't draw much power at all, and like I said, they're dirt cheap, so why not? Keeping the air circulating will also help with condensation if you add a damp rid container or something similar...

Of course, be careful with bleach and corny kegs. The two don't play nicely with each other. If it were me, I'd keep the extras in there with water or starsan or something to keep the thermal mass up. It will prevent the fridge from cycling on and off so much. How are you going to mount your temp probe for the lagering chamber?

don't have the controller/probe yet. i was thinking i'd put them about in the middle (length-wise) of the chamber on the rear wall. This would be near my secondary/serving keg. I wouldn't permanently mount the probe so that i could move it from the inside wall to taping it directly to one of the kegs. I would have a separate temp probe and cheapo rigged thermostat in the far chamber to control the fan on the dividing wall to suck cold air into the separate primary chamber.

where would you suggest?

Munsoned, I've only been at this HB thing for a few months now and I'm still bottling my beer as a matter of fact I'll probably always bottle, I dont drink much of it at home I usually take it with me places and haulling a kegerator around (even some of the cool ones I've seen on HBT) doesn't sound easy to me. Anyway, what's the deal with bleach and cornies? I'm hoping it has to do with the seals and not the ss.

New-B-Brewer said:

Munsoned, I've only been at this HB thing for a few months now and I'm still bottling my beer as a matter of fact I'll probably always bottle, I dont drink much of it at home I usually take it with me places and haulling a kegerator around (even some of the cool ones I've seen on HBT) doesn't sound easy to me. Anyway, what's the deal with bleach and cornies? I'm hoping it has to do with the seals and not the ss.

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It has a lot to do with the stainless steel. "Long exposure to a bleach solution will cause corrosion and pitting" according to cleaning section in How To Brew by John Palmer. If you are new to brewing, (Like Me) make sure you read that site a couple of times. I recommend buying the book if you can.

to revive this and pose a new question, here goes:
i'm about done the build and have placed the wall between the fridge part and ferment chamber. it is removable. the question: with 1.5 inches styrofoam insulation, do you think a temp difference of 30-35*F is possible? I'd like to keep the kegerator at 35* and the ferm chamber (when in use for fermenting) at 65-70*, depending on the yeast.

a buddy told me that difference won't be possible unless completely sealed off. A cutout for a fan (two cutouts to be exact: one in, one out) will be too much to keep a temp difference. thoughts? suggestions?

pics and my own build suggestions to come tomorrow when the battery's charged.

Very interested in seeing some pics of this, I'm wanting to do basically the same thing and my lack of knowledge on the capacity of mini fridges and such has kept me from it thus far.
I currently have an extra fridge/freezer combo that I've added taps to, a stock mini fridge, and a deep freezer that only stays about a 1/4 full. I want to make the best out of what I already have.
My fridge/freezer I currently just use for two cornies, bottles, yeast, frozen pint glasses, and hops. I'm considering just dumping it and putting the mini fridge to use as one of these. I'd prefer not to lose the freezer space by building a keezer, but that has crossed my mind to.
My goal is to still have freezer space, temperature controlled fermenting space for two (or more) 5 gallon batches and serving/storage space.

Here are some finished pics. I applaud those that take pics during the build. When I finally got down to building this, I put it together pretty quick and didn't want to stop for pics. A buddy was helping, too, and he was on a time constraint, so I had to make the best use of his time. So all's I got are completed pics. I'd be more than happy to take detailed pics of the project if you would like to see particular areas, and I can describe in full any build steps.

first is the overall build. what you can't see is the minifridge tucked away to the left, underneath my bottle storage shelves.


this is the view inside the right door. the co2 tank is hiding behind the keg, but you can see the gauges. to the left are bottle storage shelves.


basically same pic, but you can see the removable dividing wall to the right of the keg.


this is the view inside the left door: bottle storage shelves and minifridge.


this is the view from the right end of the build. this is essentially opposite the minifridge. the wall facing us (the wall behind the keg) is the removable dividing wall from pic 3


i haven't altered the dividing wall yet cause i'm hoping for more input on holding the temp difference or not.

some hindsight thoughts on the build:
1. i build a frame of 2x4s with a shell of 15/32 BC plywood on the outside of the frame, then squeezed 2 layers of 3/4" styro insul between the framing. This works great, but i then added more styro at the seems to cover the exposed framing, which left a 1.5" styro lip around every inside corner of the build. I'd rethink that somehow.
2. you can't really tell, but to cut the doors, i built the front panel, measured, then cut the top, bottom, and hinge side with straight cuts, and the latch side at a 45* angle with a skilsaw. This left what i thought would be a nice angle in the wood and insulation to help make a seal. Instead of cutting the insul at an angle, i would cut it so that it overlaps the door so that when the door closes there is a straight piece of insul for it to seal against. The angle is just too hard to make a good seal. And weatherstripping gets pushed off by the movement of the door against the angled insul. You can see the bottom ledges i have installed a piece of metal bar with weatherstripping. This works better than the angled insul. I wanted to be able to remove this bar though for ease of moving kegs, so i dremeled a crevice to insert the bar into.
3. i used shower wall material (that nice white stuff) as a base here for aesthetics, but more so for ease of sliding the kegs around. It seems slick to the touch, but the weight of a keg just digs into the rough surface. I tried the backside, but it too is not slick enough. Maybe plexiglass would work better? I imagine that would scratch too though.
4. you do not need a saw/table saw to cut the insul. It's suggested in other builds that this is the best way. I used a saw and it worked well, but a razor and a straight edge worked great too.

hello. just testing

and what are the various temps that this is achieving?

are you asking what i've actually accomplished so far?
well, it holds 60 (same as my basement) really easy , but i have a nice hole in the top waiting for a draft tower, so i haven't tested it yet. The ferm chamber isn't 100% sealed yet and seems to equalize out the the external temp. Not sure if i'll be able to hold a warmer temp in there without using a heater of some sort.

Tower should arrive early next week, then i'll plug it in and see how cold i can get it and how often it cycles. Then comes the testing with the ferm compartment/temp differential. Will post all results over the next 2 weeks or so.

nbspindel said:

are you asking what i've actually accomplished so far?
well, it holds 60 (same as my basement) really easy , but i have a nice hole in the top waiting for a draft tower, so i haven't tested it yet. The ferm chamber isn't 100% sealed yet and seems to equalize out the the external temp. Not sure if i'll be able to hold a warmer temp in there without using a heater of some sort.

Tower should arrive early next week, then i'll plug it in and see how cold i can get it and how often it cycles. Then comes the testing with the ferm compartment/temp differential. Will post all results over the next 2 weeks or so.

Click to expand...

just curious how this is going and what temps you've been able to hold?

it's worked out really well so far, as my basement has been below 60 and i've held 40 without any issues. The basement's getting warmer, about 70*F now though. I dont have a controller on the fridge yet and wasnt sure how often the compressor would run, so i put it on a timer set to let it run one hour every 3 hours. Right now it'll still hit 40 when the compressor is running, but gets to about 60 when its off. I figure i have a leak near the fridge connection, or it's all in the door seals. I'll be testing in july when it's nice and hot outside.

If anyone's following this build to reproduce, i would suggest making the doors overlap onto the cabinet, forming a seal. Currently the doors close flush onto the cabinet and I had to improvise a seal, which i dont think is solid enough.

I also put a tap tower on the cabinet which might be acting as a cold transfer point. I'll be insulating that better in july as well.

Will update with final results then. Good luck on your build/planning.

I'm planning a ferm chamber about that size, and cooling with a fridge like that, so thanks for sharing! It's nice to hear you are holding temps OK with the fridge.

RC:
if you can wait until july, i should have final results on it. I'll be moving and so will detach the fridge from the chamber, then reassemble. At that point, i'll smoke out the inside to look for visible air leaks from the outside. I'll also have a PID in a few weeks that I'll check for stable temps.

Another note, i get a good bit of water on the coolant lines which also leads me to believe i have an air leak. There are a few other build edits that I'll post at that point in time (unless you can't wait, then I'll figure it out sooner) that were done and were helpful.

Oh everything is helpful I'm not sure when I'll get my chamber built. I built the control box for it from one of those Chinese temp controllers off of ebay. At this point I just need to build the box and I should be good to go. But it could easily be July before I get there. No rest for the weary over here...

nbspindel said:

it's worked out really well so far, as my basement has been below 60 and i've held 40 without any issues. The basement's getting warmer, about 70*F now though. I dont have a controller on the fridge yet and wasnt sure how often the compressor would run, so i put it on a timer set to let it run one hour every 3 hours. Right now it'll still hit 40 when the compressor is running, but gets to about 60 when its off. I figure i have a leak near the fridge connection, or it's all in the door seals. I'll be testing in july when it's nice and hot outside.

If anyone's following this build to reproduce, i would suggest making the doors overlap onto the cabinet, forming a seal. Currently the doors close flush onto the cabinet and I had to improvise a seal, which i dont think is solid enough.

I also put a tap tower on the cabinet which might be acting as a cold transfer point. I'll be insulating that better in july as well.

Will update with final results then. Good luck on your build/planning.

Click to expand...

How long did it initially take to cool the chamber down? I'm nearly finished with my build. I turned the fridge on last night for 2 hours and it only got down to 60 in the serving side. I didn't turn on the fan to suck cold air into the ferm side yet. I'm worried that it's not going to get cold enough though. I still have to devise a way for the doors to have an overlapping seal, but I didn't feel any cold air coming from around the door, so I don't think that would be keeping it from getting colder. Did I just not wait long enough?

update:
just installed a PID into the chamber. (Pics to come soon maybe.) I mounted it to the right of the 2 doors, ran an outlet to the fridge on the outside of the chamber and one outlet basically attached to the PID on the inside of the chamber. Outside is for cool, inside is for a heating element if ever necessary. During this install the chamber got to room temps, so i can comment on balvey's question. But first, i would suggest trimming some of the overlap down where the chamber meets the fridge. I had it overlapping about 6+ inches, which actually affected the cooling abilities b/c some of the coils (in the walls of the fridge) were essentially inside the chamber and were insulated moreover! I cut off about 4" all around and it seems to be cooling better (at least not straining the fridge as much).

from about 80*F i've brought it down to 60*F for fermenting. I have about 12 bottles and 20 gallons of beer in there, so it's a lot of liquid to cool, but going about 1-3 degrees twice a day worked just fine. The compressor kicks on about once an hour, max, for about 7-10 minutes. I don't feel any leaks, but also am still looking for a solution to overlap the doors onto the chamber to make a better seal. Thinking of getting magnetic sheets, but haven't really looking into it yet.

I've given up on the idea of fermenting while storing, just because removing the wall/divider is too much of an effort. Instead I just remove whatever kegs necessary to fit what's got to ferment and allow the temp to come up. I can still serve beer at 60*F while the other's fermenting, and bottles can always just be moved into a fridge if i'm going to drink one. Not the perfect solution, but good enough. I have one fan switching on with the compressor, but would put a second in there if i had the drive to do so, just for more circulation of air. I'm planning on buying a dehumidifier as well cause it still picks up a good bit of moisture (which might indicate a leak, but it's also pretty humid here and might just happen from opening the door/s).

I'm having issues with mine. I left it run all night the other night and checked the temp the next morning to see it only got down to 60F.

My dad ( quite the handy man at a lot of things ) seems to think it needs a fan to circulate the cold air. I don't necessarily think so.

My thought is that if it was just not circulating the cold air, then the thermostat, in the fridge, would have shut off the compressor when the air in the fridge got cold enough. I don't think the compressor shut off the entire night. Could be wrong but every time I checked it and the next morning it was still running.

If the compressor is never shutting off that would make me think it's just not insulated enough, am I correct in that thought?

if you built it similarly insulated to mine, the insulation is fine. I'd say there's a/multiple leaks. I agree that a fan shouldnt be necessary. It would help probably, but not necessary. Do you have a large amount of liquids in there that were all warmer the day before? it would take quite a while to lower the collective temp of a lot of warm liquid.

I'd try and test for leaks. What i considered was using a smoke bomb and a fan on the inside. just make sure you won't burn your chamber, then just hang out and look for any smoke coming out the box. you probably won't be able to feel a difference in temps (inside vs outside) if your inside is only at 60.

good luck.