How to Modify a Thermostat to Control a Fan for a Fermentation Chiller

[Skinnbones33]

Awesome!!! been working on a pc grow case, but its getting colder than i'd like, this may very well solve my problems!!!

[19chazz76]

wow creative...im going to use this idea for my home theater component rack for better cooling...thanx for the idea..

[steeljan]

@19chazz76 Sure thing, it should work out just great for ya. You can use a super silent fan and keep it all cool and quiet. If you use a dust filter with it, you can also keep the dust out of your components. Cheers!

[MCRAUTOM]

Nice work.  I am putting one together this weekend.

[steeljan]

@MCRAUTOM How did it turn out? Work okay for ya?

[nhebert999]

I meant positive from the power source to the RH

[nhebert999]

test

[nhebert999]

Ok I am a wiring moron. I took the neg from the power source and put it on RH. Then took the positive from the fan and put it on G. The thermostat I got is a LUX DMH110 $20. Switched the fan to on and powered up. Then put the fan to auto and cool....nothing. Switched it to heat and that works. What am I missing....or do I have a bum thermostat.

[steeljan]

@nhebert999 It means the thermostat is set higher than your room temperature right now. I think the default temperature is typically 78F.

Set the thermostat temperature far lower than your room temperature, then flip on Auto and Cool. It will take a few seconds, so wait for it, ah, 15-20 seconds.

There's a couple of other things we can check, but let's see if this works first.

[terpsichoreankid]

You've inspired me SteelJan! Guess what I'm building right now... hehehe

[steeljan]

@terpsichoreankid Well, go for the gusto, build the shell right the first time. I'm still living with my thin foamboard, have to change the ice twice a day and baby each new batch with extra ice, a wet towel in the ice pan, and etc. I've got a lead on a gigantic cooler that will hold 2 fermenters with ice and my controller setup, if that falls through, I'm off to the hardware store for 3" foamboard and sealant. Great! Cheers!

[brutus605]

I really appreciate your videos--Very informative!! thank-you. Could you do a video wiring a heat source to that same thermostat ? showing steps like you did here?

[steeljan]

@brutus605 Thanks, you're so kind. I'd never need a heat source, because we have pretty non-existant winters here. But it would depend on what heat source you're asking about. A heater needing wall voltage, e.g. 120VAC would need to wire the thermostat to a relay that could take that voltage. I'd probably think up something like using a hot water bottle in a styrofoam box with this fan blowing down on it as needed to maintain temp, lol.

[OPE08]

thats the thermo that I used, but I just mounted it inside the box, having it outside would be nice...

[steeljan]

@OPE08 Super. This mod turned out to be a lot simpler than I thought it would be. I've got it mounted on the top of my ferm chiller with a triangle of styrofoam under it, all duct taped down, so I can see the temp from across the room.

[brewyourown4life]

great vid . evrything looks like it should work great. i'm going to do the same thing to the thermostat in mine, just haven't had time. thanks for the link to my vid.

[steeljan]

@brewyourown4life Cool. You're welcome. I've got to get some thicker styrofoam for mine now. I'm using 5/8ths foam board and I don't like how frequently the fan is coming on, like every 5-6 minutes. Loosing too much cold.

[yartp]

Oh yea, schematics. I actually tried to search for some on my Rite Temp., all I was looking for was the value of the thermistor. Had to just pull it and measure it myself. Ordered some thermistors from DigiKey and made some probes. I need to provide some detail footage of my t-stats on the freezers since it appears to be out of the norm.

[steeljan]

@yartp Did you put two probes on the same input, or make 'em where you can switch from one to the other? If you've got more than one on the same input, you'd have to account for your series or parallel resister values.

[yartp]

@steeljan I mounted a 2.5mm jack on the side of the t-stat. I pulled the original t-stats out of the freezers and hardwired the Rite Temp using a tranny/relay module. I keep one probe in the original location of the freezer so there's nothing hanging in side. I made a couple extras so if I want to tape one to a carboy and regulate the temp that way I just unplug one and plug in the one on the carboy. I'll take some pics.

[ligon29]

Really nice, informative vid. thumbs up

[steeljan]

@ligon29 Thanks!

[steeljan]

@brewinathome Great temp controller. So, the one you built is for controlling a chest frig to make it a kegerator or lager fermentation chiller. Is that right?

[brewinathome]

@steeljan

Yes it is, I use my old dorm fridge.

[steeljan]

@brewinathome Interesting. I turned my old dorm frig into a kegerator, holds one 3 gal corney and a 5lb CO2 tank. Maybe I should consider picking up another one of those and using your design to make a better fermentation chiller. Thanks!

[brewinathome]

@steeljan

I will shoot some video of what I did to the fridge when I get a chance. I also used it as a Kegerator as well for a while anyway, then the electric bill went up. Then the wife said I don't think so, not with that one. So options were to scrap it or find a use.

[TakeSomeAdvice]

NICE! Looking good!

[steeljan]

@TakeSomeAdvice Thanks!  Temperatures, temperatures, temperatures! So true. I've got another all-grain amber ale to make but am holding off til I get this fermentation chiller built. Wish I had the money & room for a chest frig like yours. *sigh*

[TakeSomeAdvice]

@steeljan Heheh yeah all about those temps.. from mash to ferment. Supposedly those ice baths are supposed to work really well. The chest freezer as a fermentation unit is a very low energy cost. Almost nothing. If you have temp issues.. I highly recommend one. There is one in Austin Criagslist for $40. As long as it works. These guys have trucks.. just ask them for delivery for $10 or something. You'll need a temp thing though to control it. I dont want to say you NEED it, but in Texas you do!

[ACTeslaMachineDC]

Interesting stuff SJ, I'm glad your on our side lol What happened to your finger? 

[steeljan]

@ACTeslaMachineDC Dunno about being on a side, lol, but I'm sure having fun with homebrewing! Oh, my finger, well, couple of months ago I broke up a dog fight, grabbed the big dog to pull him off the little dog he attacked. But when I grabbed him, my little finger went straight into his backbone and broke at both joints, like an accordion. Would have been healed by now but I keep taking off the splint and re-injuring it, you know, catching it on things, ouch! :-( Tks for asking. Cheers!

[78recordrepair]

Thats awestriking!!

[steeljan]

@78recordrepair You're so sweet. Figured since I'm going through this, I ought to share and maybe help out others, or maybe get some pointers. I'll show more once I get it all working in my styrofoam chiller box. Thanks

[hoppinglion01]

Wow SJ, I am so glad you did this, because I know nothing about resistors, wiring, thermisters and the like....Dare I say it (VERY COOOOOOL) lol

[steeljan]

@hoppinglion01 Thanks hoppinglion. I've seen guys showing their fermentation chillers and seen some diagrams for the wiring of the Home Depot thermostat that is no longer available. I figured since I was going to do this, that I'd set up a camera and film it, editing it down to show folks exactly how to do this as easily as possible.

[yartp]

It's Depo's t-stat that most are using, mainly because it goes down to 34F. For what you're using it for that's not a factor. Can't wait to see the rest of the build.

[steeljan]

@yartp Thanks pt!