Fermentation Chamber, Thermostat Help?

Hi, I live in Central California which, to the surprise of many, is unbearably hot during the summer months. Temperatures get above (and stay above) the 100 degree mark on a regular basis and energy out here is just crazy expensive. Basically it boils down to keeping my house at fermentation temperatures during the summer months is just not possible. I need temperature control, and keeping an entire freezer going during the summer is pretty hard on the wallet as well. I loved the idea of the Son of a Fermentation Chamber due to the effectiveness and the fact that it's easy on the energy bill (no more than a few computer fans!).

I want to build something similar out of an old dresser I have sitting around, and the dimensions are almost perfect, so it will be an easy conversion. I will have the 3 ice chambers on the top shelf (where the top drawer was) and have fans pretty much keep a circular flow of air through the 3 chambers and into the fermentation chamber and out of the fermentation chamber again into the ice chamber. I will of course still insulate and seal the entire interior. My question is this:

I will need to operate 4 fans, and I would like to do so with a digital thermostat if possible. What would I actually need to do to use a digital thermostat and have it run about 4 computer fans?

Any help is greatly appreciated!!

I'd go get a cheap spare fridge off of craig's list and an analog temperature controller at your LHBS. I'm sure your system will work fine, but I can't help to think you'll end up thinking the convenience and accuracy of it will pay off in convenience and higher beer quality in the long run.

"Cheap spare fridge" is kind of an oxymoron. Running a second fridge has a dramatic effect on your electricity bill (my dad put a second one in his garage, his bill went up quite a bit). I suppose you'd only run it when you need to, but I'm not sure if occassional usage is good for the fridge itself.

Son of a fermentation chiller is something I plan to do this summer (if time allows.) It seems like kind of a pain to put the whole thing together (I'm a n00b with DIY projects) but it seems very easy to maintain.

Stevorino said:

I'd go get a cheap spare fridge off of craig's list and an analog temperature controller at your LHBS. I'm sure your system will work fine, but I can't help to think you'll end up thinking the convenience and accuracy of it will pay off in convenience and higher beer quality in the long run.

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Thank you for the reply. The point though really is to avoid adding refrigerators to my home. I already have the kegerator and when I say that electricity is expensive, I mean it is very, very expensive. If the Son of a Fermentation chamber can maintain a constant temperature with just changing the ice every few days, then I don't see the difference between a constant temperature there and a constant temperature in a fridge. A little more labor on my part, but I would save the electricity.

It is the wiring and voltages that I am concerned with. I have looked all over for instructions on how to substitute a digital thermostat for the manual one in the instructions and how to add multiple fans but I haven't found anything yet. I just need the fermentation chamber for the summer months anyways, after that I can probably do fine with just fermenting in the average temperature in the chest freezer while it is off.

Running computer fans is simple, just get an old PC power supply or brick and plug that into the controller. I use a laptop brick to power the fans that move air from the kegger into the conditioning cabinet. I patched my controller into a power strip & plugged both the kegger & the cabinet fans into it.

Maybe this would help:

http://www.wortomatic.com/articles/Remote-Sensing-DIY-Controller-for-Less-Than-$25

+1 on the power supply. Hook up as many fans as you need, then simply plug the supply into the thermostat.

Beerrific said:

Maybe this would help:

http://www.wortomatic.com/articles/Remote-Sensing-DIY-Controller-for-Less-Than-$25

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That's pretty much exactly what I was looking for. Now the question becomes how do I add multiple fans so that I can blow the cold air in a circular pattern through 3 in-line cooling compartments?

wildwest450 said:

+1 on the power supply. Hook up as many fans as you need, then simply plug the supply into the thermostat.

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From what I have seen this would require an external thermostat, correct? Normal digital thermostats aren't going to take or power an entire power supply? Or am I wrong about this?

Does anyone recognize that running this ice box is going to take the same, or more energy than a dorm fridge would? Making ice is not free. You're going to argue that well, the fridge is already running and plugged in so making some extra ice won't matter. This isn't true at all. You put a bottle of water in the freezer, it gives its heat off into the box and causes the compressor to kick on. Making ice for a fermentation chamber is really just spending the money up front and moving it into another box where it's then consumed. Using a standalone fridge just takes out the middle man and the constant moving of ice.

david_42 said:

Running computer fans is simple, just get an old PC power supply or brick and plug that into the controller. I use a laptop brick to power the fans that move air from the kegger into the conditioning cabinet. I patched my controller into a power strip & plugged both the kegger & the cabinet fans into it.

Click to expand...

That would be a great setup if I only had the controller But seeing as how I don't have it, I was hoping to just set it up running off of a DC adapter and the thermostat if possible. If I can't do that then I already have the extra power supply laying around, so that would be the next step.

I have a 7 cu ft chest freezer that I set anywhere between 32F and 68F and have had it for over 6 months. I have not seen a noticeable increase in my power usage since getting it.

+ 100 on what Bobby M stated. Making ice is not free by any means!! I think strongly it would be a helluva lot easier, cheaper, and far superior to secure a small chest freezer and temp. controller. A chest freezer indoors at an ambient temp. of 70-80 would not run (cycle) often to maintain a temp. in the fifties. Also w/ a freezer, you could cold crash at the end of fermentation. I'm sure the ice ferminators work well, but after a while changing the ice out has gotta get like "Time to make the donuts".

My 2 cents...good luck w/ the project!!

Mike

ps. I guess us "Jersey" guys think alike Bobby.

Seems like it. I'm just an advocate of not stealing from Peter to pay Paul.

+1 on bobby

If your are buying ice, that's a $2.79, let's say a week. That's $10.20 a month, every week you are fermenting.

Take a look at the project in my sig or ThomCat333's.

It's a cabinet that I fully expect to last many years and I'll never worry about forgetting about ice or capacity issues.

Bobby_M said:

Does anyone recognize that running this ice box is going to take the same, or more energy than a dorm fridge would? Making ice is not free. You're going to argue that well, the fridge is already running and plugged in so making some extra ice won't matter. This isn't true at all. You put a bottle of water in the freezer, it gives its heat off into the box and causes the compressor to kick on. Making ice for a fermentation chamber is really just spending the money up front and moving it into another box where it's then consumed. Using a standalone fridge just takes out the middle man and the constant moving of ice.

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I see your point, but I think that running a separate fridge for the sole purpose of fermenting is going to end up using more energy than a fermentation chamber due to the fact that two compressors would be running rather than one. If the compressor kicks on for 3 hours to freeze my water bottles (and I seriously doubt that it would need to be on that long), that lasts 2 to 3 days in a well-insulated fermentation chamber. You could then argue that I use a smaller fridge for the fermenting, the problem there is that I want to ferment a couple of beers at once, and looking at my small fridge and the big shelf in the back where the compressor sits, I can't even really imagine getting one 6.5 gal. carboy in there, much less 2.

Edit: The chest freezer is an option, and I already have one of those we aren't using. But at over 100 degrees in the summer, and the ambient temp of the garage somewhere in the 90s, I still have to believe that the compressor on that freezer would have to work often enough to be noticeable on the bill. The initial cost for the temperature control and the initial cost for the fermentation chamber would probably be about the same if we are honest after all of the expensive foam board. Perhaps the better compromise is to add insulation to the freezer instead of building a cabinet. The big plus to the cabinet is that I could keep it inside, and thus keep it from fighting the higher temperatures in the garage like the freezer will. It is already to the point that I can't brew again here until I get temperature control. :-(

Bobby_M said:

Does anyone recognize that running this ice box is going to take the same, or more energy than a dorm fridge would? Making ice is not free. You're going to argue that well, the fridge is already running and plugged in so making some extra ice won't matter. This isn't true at all. You put a bottle of water in the freezer, it gives its heat off into the box and causes the compressor to kick on. Making ice for a fermentation chamber is really just spending the money up front and moving it into another box where it's then consumed. Using a standalone fridge just takes out the middle man and the constant moving of ice.

Click to expand...

Yeah, I'm 100% in agreement.

I also heard Jamil talk about it today on the Sunday Show how happy he is w/ the spare fridge w/ temp control. And remember, as long as you aren't lagering, your fridge isn't even running all the time, just enough to keep the temp at 50ish for lagers and high 60's/low 70's for ales. When you aren't using it, turn it off.

I also remember John Palmer talking about making these before he went spare fridge...one of the basic brewing podcasts, if you are interested (beware though, I remember him ending the talk w/ an endorsement for a spare fridge too).

what about making a cheap foam insulation box and setting it over an ac vent in the floor and putting your fermenters in there? Ultra cheap and won't use (much) more ac energy cost than you are using but might drop the temp in the box lower...

That's the ultracheap solution...

If you do a freezer or fridge, fill it up with jugs of water or blocks of foam insulation. The insulation would keep it from having to chill down that volume of air, and the water jugs do a similar thing (it just has to chill it once). Either may help with efficiency, since neither flows out the door when you open it like the cold air does.

nathan said:

what about making a cheap foam insulation box and setting it over an ac vent in the floor and putting your fermenters in there? Ultra cheap and won't use (much) more ac energy cost than you are using but might drop the temp in the box lower...

That's the ultracheap solution...

If you do a freezer or fridge, fill it up with jugs of water or blocks of foam insulation. The insulation would keep it from having to chill down that volume of air, and the water jugs do a similar thing (it just has to chill it once). Either may help with efficiency, since neither flows out the door when you open it like the cold air does.

Click to expand...

That's a really good idea! I would definitely do that IF it had turned out that the freezer still worked... I cleaned out and turned on the freezer the other day, and it turns out that it won't even get cold anymore :-( I ordered the temperature controller 2 nights before I turned on the freezer. Great.

So I was wondering if it would be worth it to try adding ice and fans to the freezer and hooking them up to the Ranco controller much like the Son of a Fermentation Chamber? It is a very big freezer, so I am really not sure what to do from this point forward.

It's important to think as critically as possible. Keeping a certain volume of liquid at a fixed temperature requires a fixed amount of energy period. Since we're talking about using refrigeration equipment in both cases, it's relatively easy to compare the energy inputs. The only way that making ice and moving it to where you need the "cold" would be cheaper is when the unit making the ice is WAY more efficient than the potential fridge you're comparing it to (in compressor efficiency or insulative qualities of the box itself).

Let's say it takes exactly 40 minutes of compressor run time to create your ice in one freezer. Then you move that ice to your chamber where it keeps your fermenting wort at 68F for 3 days. It would likely only take your second fridge/freezer the same 40 minutes of total compressor run time to keep the same temp for the 3 days. The difference of run time is negligable, and even if it took 5 extra minutes of run time in the second fridge, you get the added benefit of more exact temp control and less jockeying of ice (none).

Don't forget that the second fridge is not being asked to keep the chamber at 30-40F like your full time fridge/freezer. It's just keeping it below ambient.

This is just my humble opinion. There are a lot of people that build these ice based fermentation chambers and love them. I think it's silly but...

Bobby_M said:

It's important to think as critically as possible. Keeping a certain volume of liquid at a fixed temperature requires a fixed amount of energy period. Since we're talking about using refrigeration equipment in both cases, it's relatively easy to compare the energy inputs. The only way that making ice and moving it to where you need the "cold" would be cheaper is when the unit making the ice is WAY more efficient than the potential fridge you're comparing it to (in compressor efficiency or insulative qualities of the box itself).

Let's say it takes exactly 40 minutes of compressor run time to create your ice in one freezer. Then you move that ice to your chamber where it keeps your fermenting wort at 68F for 3 days. It would likely only take your second fridge/freezer the same 40 minutes of total compressor run time to keep the same temp for the 3 days. The difference of run time is negligable, and even if it took 5 extra minutes of run time in the second fridge, you get the added benefit of more exact temp control and less jockeying of ice (none).

Don't forget that the second fridge is not being asked to keep the chamber at 30-40F like your full time fridge/freezer. It's just keeping it below ambient.

This is just my humble opinion. There are a lot of people that build these ice based fermentation chambers and love them. I think it's silly but...

Click to expand...

It is kind of funny how anti- Son of a Fermentation Chamber this thread is compared with some of the others I have read. Yes, ideally it would be great to have another working fridge that I could use for this purpose, but the issue now really is space. I suppose I could replace the compressor in the freezer or something along those lines, but I just don't have the space for another fridge with this one not working... So then I would have to get rid of this one first and then get the new one, meanwhile the temps here keep getting hotter and I am not getting to brew. At this point I guess the build is just the quickest option. Plus I still have yet to see how a freezer freezing 2 jugs of water for a few hours that last a couple of days is less efficient. To me that seems like a decent tradeoff for a fridge that has to crank on the compressor multiple times every day.

I'm with you. I don't like having to run the AC all day to keep it at 68 in the house. I think 68 is actually a bit chilly to bum around the house in. I was planning the same type of chamber before I even read this topic. I think the one thing you could try is buy a sheet of the insulation...maybe even a half sheet or broken one for cheap from the Home Depot or such and test it out. Use the same amount of ice proportionally to see how cold and how long the ice does in fact last. I would think that as long as you have an air tight box, it should stay cold. Also, another idea is dry ice. You can buy a 20 lb block for about 10 dollars. If you keep it in your freezer it will last a couple of weeks. Chip off what you need and use it accordingly. I don't have much space or the money to buy another fridge. Those little ones would be nice for $110 but they are too small inside. I think this box will work till I get a house as opposed to a condo.

Ok, let me try it this way. Why not just grab yourself an "ice cube" cooler, those squarish ones. Put your carboy in there, fill the cooler with water and then insert your ice bottles as necessary. The benefit is that it's still a cooler for BBQs and such and not a unitasker.

Genius. That is a great idea. But I was actually able to trade a printer for a old dorm fridge so I will be making that fermentation box. I guess I got lucky.

I am working on a similar project, but I am using the guts from a fridge. You can probably find the info on wiring the fans, using a PC power supply, and re-wiring a digital thermostat in these links:

Using fans, thermostat, and PC power supply:
https://www.homebrewtalk.com/showthread.php?t=51604

Designing a fermentation cabinet:
https://www.homebrewtalk.com/showthread.php?t=54562

Using a digital thermostat to control a fridge:
https://www.homebrewtalk.com/showthread.php?t=65743

My cabinet construction, I will be updating this as the project moves forward:
https://www.homebrewtalk.com/showthread.php?t=65929

The most energy efficient way to do all this is to use your air conditioner vent with a temp controller, that would open up a flap to let cold air into your box when you need it. The other ideas are not taking into account the heat your fridge gives off as it creates a colder space inside. This way the heat from compressing the gas in your coolant system is vented to the outside instead of inside your home, where the AC will have to cool that air and push the heat outside (essentially). So the only rise in the electric bill will be due to the temp controller/flap and of course the heat given off by fermentation. This assumes the AC runs a fair bit for you, this would not work in winter (so those are drawbacks)

You can connect the fans in a single 'circuit', simply follow the directions from http://www.wortomatic.com/images/2008/129.jpg , just insert fans positive to negative with plenty of slack and complete the circuit, shouldn't be too difficult.

On a similar thought... has anyone gotten their fan to operate properly? I have mine switched to the 'on' position all the time but i can't get it to run on 'auto', anyone?

Bobby has the right ideas. I have a 23 cube chest freezer (CL $110) with temp controller (in Arizona) that I use for fermenting. It is off more than its on. I have been running it for about three months and have not noticed any increase in electricity. The trick is to keep it in the house, not the garage. Keep as much in it as possible to help keep temperature stable. with it full I can open it and move stuff around without it kicking on. I think the longest it has ever run was the day I plugged it in and loaded it with 2 buckets and 5 cornies at room temp. it ran for about 6 hours. now it runs for 10 mins every 6-8 hours