36 replies to this topic

[Humperdink]

FYI, damp rid is your friend.

[Given2fly]

Did it take two days to get to 54, or is that just where it stabilized?For a point of reference, my ferm chamber (~2'x2x'5' w/5000btu AC) gets down to 10°F in like 15 minutes.

It hasn't stabilized yet, it's now at 51 degrees (down 13 degrees from 64) and is still slowly decreasing. And I plan to fully insulate the walls, but I want to see if the dorm fridge will work out before installing the outer panels on the bunker. Otherwise, I'll have to remove the fridge and rework an AC unit into the design.

[3rd party JKor]

It hasn't stabilized yet, it's now at 51 degrees (down 13 degrees from 64) and is still slowly decreasing. And I plan to fully insulate the walls, but I want to see if the dorm fridge will work out before installing the outer panels on the bunker. Otherwise, I'll have to remove the fridge and rework an AC unit into the design.

Sealing and insulation make a huge difference. Before I insulated my chamber it would only get down to 35F-40F. I covered it with 1" of rigid polystyrene insulation and filled any cracks with expanding foam.Also, unless you have something that is circulating air in the chamber there is going to be a huge difference in temperature between the side closer to the fridge and the side farther from the fridge. And, yes, DampRid is your friend.

[Howie]

Did it take two days to get to 54, or is that just where it stabilized?For a point of reference, my ferm chamber (~2'x2x'5' w/5000btu AC) gets down to 10°F in like 15 minutes.

What kind of "hot rodding" did you do to the fridge to get it to cool that much? Could you use a fridge that like in an uninsulated space, like a garage, or would it drip like crazy and freeze up?

[3rd party JKor]

What kind of "hot rodding" did you do to the fridge to get it to cool that much? Could you use a fridge that like in an uninsulated space, like a garage, or would it drip like crazy and freeze up?

All it is is a typical window air conditioner with the thermostat bypassed. Nothing fancy. THis is it:I've since insulated it, but there's not much to it. The nice thing about using the AC unit is that it has a built in circulating fan, so the temp is very uniform. Also the heat exchanger on the cold side has a lot of area compared to a fridge. It'll transfer heat out of the space much more quickly than a fridge.

[Howie]

All it is is a typical window air conditioner with the thermostat bypassed. Nothing fancy.

Looks awesome. Is bypassing the thermostat difficult to do?

[3rd party JKor]

Looks awesome. Is bypassing the thermostat difficult to do?

It depends on the air conditioner. It's usually just a matter of unplugging the two connectors going into the internal thermostat and splicing them together. I've heard that some of the newer fancier ACs may be more difficult to bypass. Fortunately, there's no need for anything fancy. Around here you can pick an a used AC at the end of summer for $25.

Edited by JKoravos, 31 May 2010 - 04:44 AM.

[thool]

Mine:While my fridge is smaller, it cools *maybe* down to about 50F in the summer and 45F in the winter. I've discovered that putting a couple frozen pop bottles in there can drop the temps another 5-8 degrees on average. Moisture build-up on the evaporator coils is a concern; damp-rid will help here.I saw a project once where some dude put a reservoir of antifreeze in a full-sized freezer, and then pumped it to a cold box, where a motorcycle radiator and fan distributed the cold air. I think he used a bilge pump in the freezer, controlled by a thermostat in the cold box.

[zymot]

I have a similar project going. I have a chest freezer with a Ranco digital temp controller. Works great for fermenting, but not large enough to store all the mead and ciders I want to age long term.I have built a box out of 2X4, plywood and pressboard. It is roughly 48"L x 32"W X 32"H. I insulated it was Corning R13 on all the sides and the lid got 4" of foamcore insulation. The top is a conventional hinged lid. I can fit at least 6 carboys or the the cornies I have for aging.I will use a heating/cooling thermostat to control the temps. I will continue to use chest freezer for active fermentation stages. The only thing I am putting in here is beer, meads and ciders that come from the chest freezer and are already sitting at 60 deg.I anticiape that if I keep the dead space volume down, the only cooling power I need is to compensate for any heat added from ambient sources. What I am going to use for cooling power? I picked up a couple of these things:More info and where to buyApply 12 VDC, one heatsink sucks heat from one side and passes it to the other heatsink and there you go. If this does not work, it will be dorm fridge or window AC unit time.zymot

[Howie]

Mine:While my fridge is smaller, it cools *maybe* down to about 50F in the summer and 45F in the winter. I've discovered that putting a couple frozen pop bottles in there can drop the temps another 5-8 degrees on average. Moisture build-up on the evaporator coils is a concern; damp-rid will help here.I saw a project once where some dude put a reservoir of antifreeze in a full-sized freezer, and then pumped it to a cold box, where a motorcycle radiator and fan distributed the cold air. I think he used a bilge pump in the freezer, controlled by a thermostat in the cold box.

That's pretty schweat!

[SnailPowered]

I really like this but it has brought up a question in my mind,what is the temp that you want to ferment a lager at? My girlfriend has a dorm fridge that I'm sure she would let me turn into a chill box. Thanks!

[ncbeerbrewer]

I really like this but it has brought up a question in my mind,what is the temp that you want to ferment a lager at? My girlfriend has a dorm fridge that I'm sure she would let me turn into a chill box. Thanks!

I go with 50 degrees but anywhere from 48-52 is a good range for a lager.

[SnailPowered]

I go with 50 degrees but anywhere from 48-52 is a good range for a lager.

Awesome! I will definitely have to build one after I brew a few batches so that I can try making a lager. All my favorite beers are lagers. Can't wait to see some more designs!

[Given2fly]

The bunker is hovering around 50 degrees. That is with no fan circulating the air (wanted to first test it without, the temp gauge has been moved around as well) and the box is not finished (i.e., no insulation). So once I get a fan in place and the box insulated, I think I will be closer to 45 degrees. Although I will use the box to lager in later, that is not really my goal here. The initial reason for the bunker is that I plan to ferment some larger batches for a bourbon barrel (two 25 gallon batches). So does anyone know of an equation or online calculator that might give me a better idea of how much heat will be generated based on batch size (a typical batch seems to be a 5 degree increase) so that I can determine the ambient temperature needed?

[Given2fly]

I haven't updated this thread recently but the bunker is nearly finished, just a few finishing touches (staining etc...). Here are some recent pics:Right now it is running pretty well, I have an amber (pictured) crash cooling at the moment at ~45 degrees. I still need to get a Ranco controller to hook up to the fridge.

[strangebrewer]

Looks good! I started working on a version of a bunker on paper and planning it all out when my wife said 'Why don't you just build the wine cellar you want.'

I'm guessing you put the bubbler airlock in after primary finished. Otherwise you're one lucky man!

[Given2fly]

I'm guessing you put the bubbler airlock in after primary finished. Otherwise you're one lucky man!

Oh yeah, that was one massive blow-off during primary. Airlock went on after fermentation was complete.