School Me on Temp Controllers!

[solbes]

My brother in law has a mini fridge where the compressor runs continously; I'm guessing it needs a new thermostat. So if the dimensions are large enough, I'd like to use this as a fridge for lagers (currently can't do this) or for getting more precise ale fermentation temp control. I have a Kolsch up next where this would be perfect. I also could brew in the summer this way, but I'm getting ahead of myself.

1) I see two types sold at online stores like Norther Brewer and Midwest. The analog refridge only, and the two way Johnson digital controller. Looking at the reviews, it appears I should go for the more expensive digital controller, as some people struggle with precise control of the analog version. Also could add a heater in cold winter with digital, right? Opinions?

2) With both of these, do I just plug in the fridge to the controller, and it works? No rewiring to a thermostat within the fridge?

3) Any better or cheaper options I'm missing?

Someday I'll probably move this controller over to a keezer setup, but that's 5-7 years away (no cabin yet!). Any other help or opinions appreciated, THX!

 

[mistercameron]

I've done a little bit of research on the various options as I'm assembling my side-by-side kegorator/fermenter.

1) Digital will be more precise - it's just the way it is.
2) A plug-in controller is the most straightforward. It either allows the fridge/keezer/etc to turn on to cool down, or turns off the power altogether once the target has been reached.
3) There are other (some cheaper) options if you feel comfortable rewiring your appliance. Look up aquarium temperature controller on ebay. They run you about $25 out the door, read temps in °C (boo), but have dual heat/cool controls. The catch is that you have to know how to hook these things up in place of your thermostat or directly to the compressor - dependent on your setup. Some people make their own little control box complete with heating and cooling wall plugs so it more or less mimics some of the other controller you see pre-assembled online. I don't know if you save much money, but you end up with heat+cool whereas I think the others are cool-only. Search the forums for "ebay aquarium temp controller build."

 

[ChuckO]

I agree with mistercameron about the control situation, but have a different concern.

It's possible that the compressor is running all of the time because the unit has leaked freon and can't keep up with he cooling. Is it getting too cold, or just barely cool inside? If it's too cold then you are probably right that it is the thermostat. If it's not really cold then there might be more problems to look at before going further with external temperature control.

 

[Bob_T]

For a very good, low cost, heat/cool temp controller read this:
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/

It works great...my total cost ended up about $30...

But I do agree with ChuckO that this freezer you're looking at may be kurfunked...so check it out.
If it is...craigslist is your friend...

 

[solbes]

I headed over yesterday to get some inside dimesions. Looks to be 13" deep x 24" high. I need 22" minimum for my primary w/ airlock and it will be line to line for height with a 5 gallon carboy w/ airlock. So I think I'm just barely large enough, especially if I push in the airlock a little deeper on the carboy. He also had it running for about 10 minutes before I got there and it was already getting pretty cold. It's one of those units where the internal freezer is the only thing carrying refridgerant (it was very cold).

I'll check into some of those lower cost options too, thanks for that. If nothing else looks quite as easy, I have no problem spending $70 on a digital 2 way controller though. Gotta love free fridges!