AC Unit Fermentation / Beer Cellaring Closet

My newest project (seems like I have a lot of these since I started brewing ) is to turn the closet in my bar downstairs into a fermentation / cellaring closet.

The plan is to use a 5000 BTU ac unit to cool an approximately 3 x 8 x 7 area inside the closet. I'll be insulating it with R-13 batting and probably 2" polystyrene foam board.

Heres a pic of the closet from behind the bar (old picture, my camera needs charged).

The left wall is a semi exterior wall, it leads to an unheated garage. The right wall is the adjacent to the stairs, and the back wall leads to the other room in the basement:



I'll be trying to update this thread with pictures and details as the project progresses. As of now I just have the AC mounted in the rear of the closet, and thats about all, nothing exciting.

Are there any real issues with using this area for both fermentation and long term beer storage? I would mostly only be fermenting ales, lagers only if after testing I can get the temps down that low. I would also like to maybe store some wine in this closet as well. If I go the lager route I may have to create a separate chamber to keep the overall temps consistent.

where does the warm air from the AC vent to? are you going to run duct outside?

I was thinking either letting it vent naturally (there is a large hole where the piping / drains run in the back left out to the laundry room) or run ducting down through the space under the stairs and venting there. Its alway cool downstairs since one entire side of the house is underground, and I dont really expect the thing to be running very frequently honestly. No great way of getting it outdoors other than drilling through concrete block or long runs of ducting. I'm not sure that is absolutely necessary but if everyone else thinks so I might buck up and and go for it.

Well the AC unit will vent warm air out the back as it cools, if you dont vent it out of the chamber your cooling efficiency will suffer greatly.

Otherwise, as long as you insulate the closet well it looks like a great space. Maybe add some shelving units so you can maximize the space!

I really wish I had a basement

Wellllll, I did something similar and I can tell you some issues I had/have. First though, if you don't put the A/C through to the outside (or some other room), there is no way for the heat exchange to take place and your room won't really cool. I put a lagering chamber inside the ale/beer storage room. This is inside of my shop, so during the summer it get's in the high 90's to 100F fairly routinely. This is a refridgerator with an attached cabinet. Long story short. The a/c I used had to work too hard to remove the heat generated by the lager chamber. The a/c went out and I superheated my storage room. When I noticed the a/c not working, I opened the door and my thermometer showed over 100F. Also, when the beer is being moved in and out and around after brewing, you will lose a lot of "cool" from the storage room. I will probably figure out how to properly size my window unit for the correct heat removal and try it again. On top of all of this, I "no chill" so I add 11 gals of hot wort to the area also. Luck, and let us know how it progresses. - Dwain

*** I started typing before there were any replies, so that's why I repeated their concerns

Thanks for the responses. The hole that is there is approximately 1.5 square feet (a little over 1 entire concrete block taken out. I was planning on heavy insulation in between the hot/cold interface and natural ventilation, but maybe I'd be best making a hood for the hot side of the unit and venting though there.

Even in the dog days of summer, this space does not get above 80 degrees, so I don't think I'm going to have to deal with 100 degree temps. Plus I dont use 'no chill'. What temps were you shooting for in the chamber Dwain?

I guess I don't necessarily want to separate the closet for lagering. I could just pick up a small freezer and put it elsewhere if I decide to go down that path.

You can't just set the a/c in the room and expect it to cool the area at all. All you are doing is moving air around. The unit is absoring heat in the front, and releasing it out the back. The two must be seperated from each other for it to work. You also need to seal that hole around the pipes if you expect it to be very efficient.

KCBrewer said:

You can't just set the a/c in the room and expect it to cool the area at all. All you are doing is moving air around. The unit is absoring heat in the front, and releasing it out the back. The two must be seperated from each other for it to work. You also need to seal that hole around the pipes if you expect it to be very efficient.

Click to expand...

Sorry if my prior posts werent very clear about this, but I am updating the thread as I work on the project. Maybe the pic is misleading since I had the temp controller kinda set up to test if it would even run and also how loud the compressor is.

Of course I will be separating the cold and hot areas. If you look at the picture you can imagine the entire area behind the AC blocked off from the rest of the closet (well insulated also), and that area being ventilated through the hole in the back of the wall to the laundry room, or ducted with insulation down to the right under the stairs.

I will be building a somewhat removable bulkhead around the pipes, along with more insulation.

Basically the entire cooled area will be completely sealed off. A new door is also in order.

Okay heres some crude sketches to help:

LAYOUT PLAN:




PROFILE FROM RIGHT:

Okay, misunderstood what you were doing there. That looks like it would work, but you probably will want to give it a more direct exhaust outside that area, especially if you want to get to lager temps.

Thanks for the input KC. What about a fan pushing air out into the laundry room set to run when the compressor is on?

What temps were you shooting for in the chamber Dwain?

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I was just trying to hold the chamber at 70F during the summer just to see if it would. I have the room very well insulated and it could barely keep up. At 70F, the temp is still a little warm for an ale fermentation. Part of the problem is if I leave the shop closed up while I'm gone, the interior will get well over 100F and part of the problem is I went with too small of an a/c. either way, this is your thread. I just don't want people making the same mistakes I did.
I think if you seal the room, new door and route "heated" air outside, you'll be fine. Although, if you "push" the air into the laundry room and it's not vented, that room will pressure up and you will lose effieciency on your a/c. - Dwain

Some type of circulation outside of that area would make all the difference. Even a bathroom exhaust fan mounted near the exhaust of the a/c, and a vent pipe run out through the hole by the pipes would help. Just run it out a few feet past the opening, then leave the rest of the opening how it is so fresh air can return.

I would start with something cheap like this for $13.97.
http://www.homedepot.com/Bath/h_d1/...splay?langId=-1&storeId=10051&catalogId=10053

This plus and some 3" vent pipe would get you going. Just mount it facing the exhuast of the a/c.

If that doesn't cut it, one of these would work excellent. A little pricey at nearly $60 though.
http://www.homedepot.com/webapp/wcs..._-100047556-_-N&locStoreNum=3006&marketID=129

KCBrewer said:

Some type of circulation outside of that area would make all the difference.. Just run it out a few feet past the opening,
This plus and some 3" vent pipe would get you going. Just mount it facing the exhuast of the a/c.

Click to expand...

I do the same thing for my glycol chiller, exhausting the hot air through the ceiling with a fan.
During the ice cold winter months, 59° F in the brewery I remove the exhaust and let the warm air warm the beer sampling area.



Cheers,
ClaudiusB

Just picked up a 13 dollar bathroom vent and some 3" flexible ducting at Lowes. This will be my project tonight. I'll try to get some better pics up.

Question: What kind of precautions should I take as far as condensation build up on the hot exhaust side of the AC unit? The unit has a drain connector that you can attach flexible piping to. Should I just run some piping down through the bottom of the AC manifold and into a 5 gallon bucket? Or will I not really have to worry about this since I will be exhausting the moist hot air into the other room? Seems like that condensation is going to want to build up somewhere...

I'd be sure to use the flexible drainage hose. Even if it never needs it, better safe than sorry. Also, I'm not sure where your clothes drier is, but could you duct the AC exhaust into the same vent that goes outside? Just a thought.

I would very strongly suggest wrapping the ENTIRE area that you're going to be cooling with a vapor barrier. As soon as you get any kind of significant temperature difference between the area you're cooling and the other areas, the closet is going to suck in a ton of moisture and you'll end up with two things: mold and a frozen AC unit.

If the basement is normally 70 and you're only going to 65... maybe it won't be a big problem... but again, I would strongly recommend a vapor barrier NOW, instead of realizing you need one later and you have to rip everything out because of mold.

i have a small "walk-in" cooler I built with a tiny AC window unit. It is nothing but a 7/8 foot long, four foot wide and 5 foot tall tiny "room" that I framed in and built. It is as air tight as I can get it and the entire thing is wrapped in 6 mm plastic as a vapor barrier and I STILL battle moisture in there.

I keep it much more as a kegerator since that is where I keep my kegs, bottles and run my lines from so it is a lot colder than a fermentation cabinet but I would still be very leary about moisture.

ClaudiusB said:

I do the same thing for my glycol chiller, exhausting the hot air through the ceiling with a fan.
During the ice cold winter months, 59° F in the brewery I remove the exhaust and let the warm air warm the beer sampling area.

Click to expand...

Claudius, have you ever consolidated the details of your glycol system? I have seen references to the controllers, solenoid valves, the chiller itself... Curious to read the whole system details if you already have them all in one place.

Cheers!

mjohnson - I will probably just run the drainage hose to a bucket for good measure. I hope that after the initial drawdown of moist air, it shouldnt be needed much. My dryer is actually in the other corner of the room, but I probably could run the ducting through a drop ceiling over to that location if need be. I think I'll see how much the interior exhaust affects the laundry room and keep the dryer vent idea in my back pocket. Thanks for the idea!

Cape Brewing - Thanks for the input on vapor barrier. I have also bought some 4 mil plastic and will be sure to install a vapor barrier on the "hot" side of all insulation, i.e. I will be installing the vapor barrier on all surfaces before the insulation goes in.

I would think a bucket would be sufficient for condensation drainage if you have it sealed up well. That's how a refrigerator works, which is basically what you are building, just slightly larger. A refrigerator pulls the condensation out, then drains it to a pan under the fridge where it evaporates from. If the bucket is in the room the heat is being dispersed to, it will help with the evaporation.

You may have trouble with freezing of the coil on the a/c. I've read several other posts where people doing this have had that same problem. I sent one person on here the parts (defrost timer, burner, bimetal sensor) from a fridge and made a wiring diagram on how to wire it up. I haven't heard back on how it worked out for them, but it should solve any freeze up issues. It just takes a little work to hook up the parts. If you run into the same problem, just let me know. I have access to a lot of used appliance parts and can send you the same stuff for the cost of shipping.

I'm getting ready to build a sort of double door fridge/ferm chamber in my garage once I make a little more room. I plan to have one side at fridge temps and the other at ferm temps and will be using 2 window units. I'll have a little more hands on experience with getting these parts hooked up to a window unit once I do. The only real issue would be getting the defrost burner mounted under the coil. Other than that, it's just little wiring.

This site never ceases to amaze me with all the helpful people. Thanks KCBrewer and everyone else that has posted thus far in this young project.

I have also read about the coils freezing over in these types of projects. My first idea would be to keep a fan running inside blowing over the coils to keep air circulating. If that doesnt work then I may be sending you an email KC. Thanks again!

kpr121 said:

My first idea would be to keep a fan running inside blowing over the coils to keep air circulating.

Click to expand...

That alone may do the trick and would be as simple as wiring the fan on the window unit to run constantly, using the thermostat to control only the compressor. No need to add another fan.

Good luck and be sure to keep us updated, with pics!

That is exactly how I have mine wired. The fan on my AC unit has been going 24/7 almost three years straight. When the compressor kicks off, if any frost has collected on the coils, the fan almost instantly defrosts them.

That is exactly how I have mine wired. The fan on my AC unit has been going 24/7 almost three years straight. When the compressor kicks off, if any frost has collected on the coils, the fan almost instantly defrosts them.

Click to expand...

When I bought my a/c unit, the fan ran all of the time. I checked the manual and it said that some of the models did that. The unit quit working after one summer. I attributed it to the fan wearing out on a cheapo unit. Now I'll have to do some troubleshooting. As soon as I put my brewstand back together, get my computer squared away, set my shop up....

Funny because I actually remember that unit running all the time when I had it in the living room window last year. That would save me some wiring work. Although it could also crap out on me quicker since it already has a couple months of run time on it...

So I finally got around to working on this, started the vapor barrier, got the AC unit and vent fan mounted, ran the ducting through the hole to the laundry room, and got some preliminary wiring done.

Heres some pics:

Looking into the closet mid-vapor barrier-ing


Looking up behind the AC Unit:

have most of the insulation up, and paaneling done on 1 wall. My current issue is how to get the door sealed.

I just used heavy duty weather stipping around the edge of the entire door... and then made it so I would have to really close the door tight for it to latch... seems to work.

Yea I think I will need a new door. That slotted 'saloon' style door is not going do very well keeping cold air in...

Ehhhh, yeah. I think you need a new door.

I also tossed a little bucket of DampRid in my walkin. I wasn't sure it was going to help much but it seems to be helping a ton. I never got a LOT of moisture but now I get NONE

Good call on the DampRid. I have some of that in my under bar kegerator and it does wonders for decreasing condensation.

Are you finished with this project yet? I'm curious to see how it turned out.

Nope it has fallen to the bottom of my todo list. With spring just around the corner and lots of outdoor projects coming up I doubt I will get to this for a while. At least until I get sick of using a swamp cooler for ferm...

I did get a hollow core door for 5 bucks at a construction reuse place. Just being lazy I guess

kpr121 said:

I did get a hollow core door for 5 bucks at a construction reuse place. Just being lazy I guess

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You might want to add some foam insulation to the back side of that door as a hollow core has very little insulating value.

Hoosier-Brewer said:

You might want to add some foam insulation to the back side of that door as a hollow core has very little insulating value.

Click to expand...

Good heads up, I know I originally thought about doing that but its been so long that I kinda forgot haha!

Man I really need to get going on this thing. The small window of perfect fermenting temperatures in the basement is dwindling. I had a good setup too, where I would have the ferm buckets on chairs and move them closer or further away from the fireplace depending on what temp I wanted them to be at!

I'm brainstorming what to do in my basement now too. I brewed 2 days ago and I have been keeping the ferms in the spare bedroom, but when I got up this morning the temp on the primary was 74. I had to hurry up and set up a swamp cooler before work, luckily it helped and the temp is at 66 now. I don't like that much of a swing so I need to build a closet or something in my basement near the bar that is under construction, not sure what to do with it yet. Anyway, I'm subscribed so I can see how yours turns out. Good luck.

Well, I convinced myself (and the SWMBO) that tonight was a ferm closet kinda night. Went to HD and picked up hinges for the door, some foam board insulation, more vapor barrier, and one of those contractor lights that you can plug directly into an outlet.

Finished all the vapor barrier installation. Got the entire chamber insulated besides the door. Installed the hinges on the door. Plugged the light into the temp controller (along with the AC unit and exhaust fan. Set the temp for 53 deg F, and it is churning away now. It took less than 10 minutes to get down to 59 from around 70, but now it seems like the compressor is kicking on and off. I have the temp probe (is there only one?) directly on a 45W lamp, the lamp housing is hot to the touch.

What do I have going on here?

Edit: Heres some crappy pics from my cell phone:

Could there be some sort of safety shut off that turns the compressor off even if the temp probe is reading higher temperatures? The lamp and probe is hot (maybe too hot) to the touch.