Please help with fermentation chamber - Window AC or fridge.

I'm looking for some advice on a fermentation chamber.

Current situation: Living in N Minn, Summer gets up to 95, Winter gets -30 (both temps in F), I have no basement, fermenting happens in the house on ground level.

So, my problem is 2-fold. 1) My swmbo doesn't like the 15 gal of beer fermenting in 3 containers around the house. 2) In the summer our house gets to abou 75 F - upper end of yeast fermentation temps. THe best place for the chamber is likely the garage unless i can build something that looks nice like furniture. I also have more room in the garage too.

SO, if i build a box style chamber what are the pros and cons of using a fridge vs window air conditioning unit as i see those are the more popular ways to go. Last resort is that i only brew beer in winter months when the house is a more cosnistant 65-68 degrees.

I think a fridge might put off less heat. Plus the fridge will be quieter. Just get a mini fridge, build a nice looking insulated cabinet and use thermostat controlled low noise (QUIET) pc fan to move the air from the fridge to the chamber as needed. Fill the fridge with some kind of drinks and then it serves two purposes.

SHMBO might like getting some of HER fridge space freed up. ( I know it is a popular topic around my house. )

I agree with the small refrigerator concept. Just make sure the size of the cabinet is not so big that the capacity of the refrigerator can not properly cool the space. Using a small fan inside is a necessity. You want good airflow in and around the space.

Salute!

This is the same thing I've been thinking about. I can build a fermentation chamber in my attic...get's up to about a 100s f in the hottest part of the summer and in the 40s f in the winter. I've been thinking a mini fridge in the summer and a fermwrap or heat belt for the winter.

Would a dorm fridge be big enough?

I chose the window AC route because my cabinet size is not limited should I want to expand (I can currently fit 4 6gallon carboys in the chamber), I can keep fermenting beer at lager temps ~48-50 even in the dead heat of Oklahoma summer in my garage, and should I ever kill the compressor I can just pick up another used AC off craigs list and swap it out, no major surgery to my chamber.

If you're using the garage, build a room (maybe 4x8) around a garage window and use an AC unit. you could fit a number of fermenters in it as well as homebrew supplies...easy walk in cold room

not sure i want to make a cold room, just a room at 68 +/- 2 degrees or so.

strat_thru_marshall said:

I chose the window AC route because my cabinet size is not limited should I want to expand (I can currently fit 4 6gallon carboys in the chamber), I can keep fermenting beer at lager temps ~48-50 even in the dead heat of Oklahoma summer in my garage, and should I ever kill the compressor I can just pick up another used AC off craigs list and swap it out, no major surgery to my chamber.

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this is interesting. do you have pics? what did you do for the walls - 2x4's or 2x2's, plywood or dry wall, etc????

This is not my post= https://www.homebrewtalk.com/f51/side-side-fermentation-chamber-build-105054/ = but this is in my future. I really like it side by side refers dirt cheap 50-75$

a two stage temp controller= http://www.etcsupply.com/ranco-etc211000000-stage-prewired-temperature-controller-p-110.html=

small heater 20$

x

bump ba da bump bump

still looking for more ideas/suggestions

I would not go with an AC unit for cooling/heating up to 2 fermenters. I'd go with a fridge or freezer, used on Craigslist.

The fridge will be insulated and will run quieter and be more energy efficient. Plus, of you put a heating device in there, you can use the controller to heat your fermenter in the winter. Same efficiency rules apply there too.

I've found Practically free fridges on CL and have seen plenty on there for $50-75 range.

kegtoe said:

this is interesting. do you have pics? what did you do for the walls - 2x4's or 2x2's, plywood or dry wall, etc????

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I build a really basic workbench for my garage out of 2x4's and plywood, and then I enclosed the underside of the bench with sheets of plywood. The entire inside of the box is insulated with double layers of 1.5" pink foam sheets like you can buy at home depot.

I had to hack the AC unit, and re-route the temp probe out the back of the unit so that the compressor doesnt kick off when temps get into the 60's. It was very easy to do.

Between plywood, foam, craigslist find AC, and construction materials I think I came in at under $100 for the entire build. I'll shoot some pics this afternoon while I'm kegging a few batches and post them up here. A word of warning, it was meant to be cheap and reside in the garage...so its ugly!!

fair enough strat, looking forward to the pics.

I'm pretty sure when I finally get around to building my fermentation chamber, I'll be using an AC. The main reason is that I think condensation will be much less of a problem. It can be quite humid here, and i always have lots of standing water water while fermenting in my chest freezer. I'll also be a lot less constricted on space and shape of the chamber.

If you want to go real simple you could buy a cheap full sized fridge on craigslist and add a temp controller. If you build a shelf and remove the door shelves you'll probably be able to fit 4 carboys with room to condition some bottles underneath. I use two of them for a total capacity of 8 carboys. Here's what I did to convert mine-http://www.instructables.com/id/Converting-a-fridge-for-fermenting-beer/

kegtoe said:

fair enough strat, looking forward to the pics.

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Heres a couple quick shots:





note the temperature probe antennae poking out the top of the ac unit in the 2nd picture. I had to drill a hole in the casing and move that probe from the front grill of the unit to the back. This way the compressor doesnt turn off while the unit is running. it's controlled by a Johnson digital controller, with the temp probe taped to the side of the carboy inside.

JuanMoore said:

If you want to go real simple you could buy a cheap full sized fridge on craigslist and add a temp controller. If you build a shelf and remove the door shelves you'll probably be able to fit 4 carboys with room to condition some bottles underneath. I use two of them for a total capacity of 8 carboys. Here's what I did to convert mine-http://www.instructables.com/id/Converting-a-fridge-for-fermenting-beer/

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Juan, that is my current set up. I took my pre-keezer garage fridge that has 2 taps on the outside and added a Johnson A19 controller. I have a wodden shelf on the bottom that i painted white and tehn covered with bar top epoxy. I can only get two 5-gallon fermenters in it though. I'd like to have 3, maybe 4.

strat, how long would you say that AC unti runs. I guess i dont understand why you are using an external controller.
1) i thought that if an external controller was used it shuts the unit down and when that happens they have to be physicaly reset.
2) isnt there already a "built in" temp controller on the AC unit itself??

sorry if these questions seem dumb, i'm a nube with the AC unit thing.

kegtoe said:

strat, how long would you say that AC unti runs. I guess i dont understand why you are using an external controller.
1) i thought that if an external controller was used it shuts the unit down and when that happens they have to be physicaly reset.
2) isnt there already a "built in" temp controller on the AC unit itself??

sorry if these questions seem dumb, i'm a nube with the AC unit thing.

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The most it ever runs is 5 minutes or so an hour, and thats in the heat of the summer. During cooler times it might cycle on for 3 minutes ever 2 hours or so.

The external controller allows me to set the temperature to with +/- 1 degree. The internal thermostat could never be that accurate, and could not monitor wort temp, only air temp. The external controller allows me to place the temperature probe against the side of the carboy, so I am actually measuring the temperature of the beer.

The power cord of the AC unit plugs into the external controller. The Johnson controller turns "on" when the temp is too high, providing power to the AC. While the AC is running it blows full on cold since the temp probe is rerouted out the back of the unit. It "thinks" the room temp is the ambient temp of my garage, so it keeps the compressor running the entire time it has power. With the compressor never kicking off, the unit will put out air below 20F pretty easily. It can drop 5 gallons of fermenting wort 2-3 degrees F in just a few minutes. Its great for maintaining temps, but if you try to take a carboy from say 70F to 50F you will freeze up the coils.

Once the temp drops to 1 degree below target temp, the controller kills the power. Not sure about a physical reset, but my unit does not need one. It turns on when the power kicks on and turns off when the controller kills power.

very cool. i was looking at menards a while back 'cause they had a big sale on ac units. most of them said something like reset needed in the event of loss of power. im assuming the johnson controll acts like a loss of power. I have to of the a-19 controllers; one for my freezer wich holds 38-42 degrees and one for my garage fridge that is a temporary fermentation chamber.

say you had your unit plugged into a regular wall outlet and it was running. if you unplugged it and plugged it back it would it keep running?

kegtoe said:

very cool. i was looking at menards a while back 'cause they had a big sale on ac units. most of them said something like reset needed in the event of loss of power. im assuming the johnson controll acts like a loss of power. I have to of the a-19 controllers; one for my freezer wich holds 38-42 degrees and one for my garage fridge that is a temporary fermentation chamber.

say you had your unit plugged into a regular wall outlet and it was running. if you unplugged it and plugged it back it would it keep running?

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yep. sure does. Thats basically how the Johnson controller works. Keep in mind that it's a unit i bought off Craigslist from a dude who had it buried in a garage that looked like a garbage dump. It's probably 15 years old, all analog controls.

I'd recommend this route because of three things.

1. easy and cheap to replace. I think I paid him $25 for it.

2. analog controls are easy to mod and bypass. rerouting the temperature probe was super simple, and the knob for the thermostat control was just a pot with a set screw that determines the thermostat's range. I was able to crank the set screw all the way down so that when the knob was set to coldest it was blowing below freezing air, rather than 50 degree air.

3. You can custom build your cabinet as big or as small as you want. Mine will hold 4 carboys, but there are builds on here where guys use window AC's that are hacked like mine to do full on cold storage rooms.

Just remember, this is great for maintaining temps...but if you strap your temperature probe to a 70 degree carboy and set the thermostat to 50 it will run non-stop, never cycling the compressor which can lead to freeze ups. You need to be able to cool your wort to pitching temps PRIOR to putting it in here, or you need to carefully monitor the unit and step it down manually (ie. set it to 68, next hour set it to 65, next hour set it to 62).