Help w/ fermentation chamber

I would like to build a fermentation chamber that is cooled using my kegerator. My initial thought was to run two cpu fans through the kegerator wall, into the chamber. But I think it would be too cold in there. My kegerator sits in the high 40's and my chamber I would like in the mid 60's. Could a temp controller be connected to a fan so that when it raised above a temp. it would pull some of the cooler kegerator air out to lower the temperature? Better ideas?

Along the lines you're thinking -
I'd build a separate well-insulated box, and yes, with a temp control, move some air from the kegerator over to the fermenter...Test first, but sounds plausible.

so you have a duct that is on a temp controlled valve coming from the keezer / kegorator into your fermentation box, when temp in box get to xx degrees the valve kicks open letting cold air from the keezer / kegorator into the fermentation box

is this is idea your thinking of?

-=Jason=-

HG - plausible is good.

Flo - yes that is exactly what I was thinking.

im sure some electronic guru can whip this up no problem


-=Jason=-

http://i77.photobucket.com/albums/j56/sketerbuck/fermentor.jpg

This is very close to what your talking about. The freezer in the background in controled to 35 degrees. The freezer in the front does not work so I move cold air to it from the working one to keep it at 50 degrees. It works very well and is controled by a regular household thermostat.

Two thoughts that I think are obvious but feel I should point out

1) you would then have a ferm chamber and kegerator right next to each other and essentially wouldn't be able to move them around (may change your mind in the future)

2) Definitely make sure no coolant lines running where you want to put the holes in the kegerator.

Sketer that is more or less exactly what I want to do. Is that tangle of wires as complicated as it looks?

smmc- I did think about the flexibility of the design but I have 3 years minimum before it's time to change settings and by then I can use it as an excuse to upgrade.

sketerbuck said:

...
It works very well and is controled by a regular household thermostat.

Click to expand...

I have contacted Honeywell and all they said was "They ALL use 24v, sorry." Fans are 12v, I figured it SHOULD work. Now I know it DOES.

Details , PLEASE.

Ok here it how you do it. You need a relay with a coil that works with 12v dc. You can get this at radio shack. You also need a 12v dc power supply (an old power cord for charging something) just look at the cord and it will have the output voltage. If you cant find one you can buy a universal one at radio shack also. The 12v goes to the thermostat (which works like a switch)then from the thermostat to the relay. When the thermostat hits the temp its set to then it sends power to the relay. The relay has normaly open and normaly closed contacts. You want to use the normaly closed contact. I will post a sketch that will be easy to follow. When I first started this project I used three differant thermostats that did not work. What you need is a basic heater thermostat not an electronic one. You can find them at Lowes for about ten bucks.

link to Radioshack 12v relay with coil ? all parts I am familiar with but that relay and coil

-=Jason=-

images

in the box

5VDC/1A SPDT Micro Relay
Model: 275-240 | Catalog #: 275-240
See technical specifications
See features of this product

The one I used looked like this one but was 12v. Any 12vdc relay will work

A relay is an electrically operated switch. Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions and most have double throw (changeover) switch contacts as shown in the diagram.

Relays allow one circuit to switch a second circuit which can be completely separate from the first. For example a low voltage battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay between the two circuits, the link is magnetic and mechanical.

The coil of a relay passes a relatively large current, typically 30mA for a 12V relay, but it can be as much as 100mA for relays designed to operate from lower voltages. Most ICs (chips) cannot provide this current and a transistor is usually used to amplify the small IC current to the larger value required for the relay coil. The maximum output current for the popular 555 timer IC is 200mA so these devices can supply relay coils directly without amplification.

I have built a Fermentation chamber and I can say with 100% certainty what you are proposing will work. I used a window AC for mine and built 3 separate compartments but the build is essentially the same.
Now for my 2cents. I used a LUX brand digital thermostat you should be able to find one for about $25 to $35 on eBay the reason I like this brand is that you don’t need a power supply to make them work they work off of 2AA batteries and have 2 relays built in 1 for cooling 1 for heating (obviously you would use the cooling side) they are rated for 24v not sure the amperage but they will handle a 12v supply for a computer fan no problem. I am sure there are other brands that work the same this is just the one I have experience with. Basically it would be the same as the drawing sketerbuck drew up minus the relay because it is built in.
If you want to go the easy route just mount the thermostat inside your chamber and you should be fine. If you want to get super precise control you could open the thermostat and remove the themoster and put it in on a wire lead that can either be taped to the side of your fermenter or potted into a thermwell, after all the temp of the air in the chamber is not the temp of your wort.
When your run your duct from your kegerator as said before be careful of your coolant lines, also run your duct as high on your kegerator as possible cold air is heavy and if your duct is at the bottom cold air is going to go into your chamber whether you want it to or not it will also make your kegerator work harder if it is mounted low because of the loss of cold air needlessly.
Lastly insulate insulate insulate, I would make sure you have a way to cut off your chamber for those times you don’t have anything fermenting.

edit: honeywell device I have at home WILL NOT work.

-=Jason=-

sketerbuck said:

Ok here it how you do it. You need a relay with a coil that works with 12v dc. You can get this at radio shack. You also need a 12v dc power supply (an old power cord for charging something) just look at the cord and it will have the output voltage. If you cant find one you can buy a universal one at radio shack also. The 12v goes to the thermostat (which works like a switch)then from the thermostat to the relay. When the thermostat hits the temp its set to then it sends power to the relay. The relay has normaly open and normaly closed contacts. You want to use the normaly closed contact. I will post a sketch that will be easy to follow. When I first started this project I used three differant thermostats that did not work. What you need is a basic heater thermostat not an electronic one. You can find them at Lowes for about ten bucks.

Click to expand...

Bing!!! I think a light switch just went off in my head. [Owwww!!!]

The relay being NORMALLY closed will open when the HEATER thermostat says “I need heat.” and the fans will stop. It will then close when the HEATER thermostat says “I am warm enough.” Which will turn the fans on.

Brilliant!!! Talk about thinking outside the box. Thanks Sketer.

You got the part number for the relay from Radio Shack?

That is exactly how it works the "heat" is turning off your fans. BTW are you using two fans one in and one out? This is how I did it and it works well. I dont have a part # for the relay but if you go into radio shack they can hook you up.

I have been contemplating another method for a while.
I have a couple of old outdoor electronic timers lying around from an old project.

Like this:
http://www.homedepot.com/Electrical...splay?langId=-1&storeId=10051&catalogId=10053


Instead of buying a second $70+ Digitial temp controller, (already have one for the kegerator) I was thinking of hooking up the fans to this timer, and having the fans run for 30mins a few times a day. If the fermentation cabinet was well insulated, you might be able to hold pretty decent Ale temps. Of course you could always make the intervals longer, or have more "on" times in a day.

But for about $10 and maybe a few days of testing with a carboy of water, I think it might be worth it.

tsb22 said:

I have been contemplating another method for a while.
I have a couple of old outdoor electronic timers lying around from an old project.

Like this:
http://www.homedepot.com/Electrical...splay?langId=-1&storeId=10051&catalogId=10053


Instead of buying a second $70+ Digitial temp controller, (already have one for the kegerator) I was thinking of hooking up the fans to this timer, and having the fans run for 30mins a few times a day. If the fermentation cabinet was well insulated, you might be able to hold pretty decent Ale temps. Of course you could always make the intervals longer, or have more "on" times in a day.

But for about $10 and maybe a few days of testing with a carboy of water, I think it might be worth it.

Click to expand...

thats an awesome idea using those timer like that.

-=Jason=-

My 50 degree section turns on for a few min. 20 times a day. I think your timer will have your temps all over the place.