New Chest Freezer for Fermentation

I just purchased a 14.8 CF ge chest freezer to use as a fermentation chamber. I live in N. Florida and experience temperature swings that would necessitate warming carboys while in the chest freezer, because ambient temps dip below freezing at night.

I am considering purchasing a Johnson digital temp controller to regulate the cooling function of the freezer. Any suggestions as to how to increase the temp. of the fermenters once ambient temps decrease too low? And how to regulate the warming/heating?


Check out the controller I have linked in my signature line. It will run in cooling mode or heating mode. Like the digital Johnsons. The difference, besides price, is you need to open the Johnson controller up to change the setting. The ebay model is changed with pushing the program button.

I don’t think you are going to need to heat and cool at the same time? If you have a mini space heater in the freezer set to turn off at 60*, the beer should not rise much above that.

If you think you will need to have both running, you will need 2 controllers. I don’t think there is a controller that will operate in both modes at the same time.

ok. that makes sense. I was looking at a 2 stage Ranco controller, but my limited electronics experience has me a little intimidated.

Thanks for the quick response.

Do you have any suggestions for the space heater?

You can buy the Ranco/Johnson controllers pre wired. I think with both you need to open the door and move a pin from cool to heat.

The controller I have linked, you need to wire. A simple job. I linked the wiring diagrams and some videos to help with it.

For a heater, any of the small ceramic type heaters you might put in a bathroom to take the chill out while in the shower will work. Available at any small hardware store or the big boxes (walmart/home depo/…) ... eater.html

How does the quality compare to the Johnson unit? FWIW, i have the Johnson and it works great for me.

Myself and a couple locals have been using this aquarium controller for a year or so. Other people on NB and Homebrewtalk have been using them also. For how long, I don’t know.

The data sheet on it say 10amps. Opening the controller and looking at the hardware it is stamped 15amps.

I have a two-stage ranco for my ferm fridge and it works really well. I bought it unwired but it’s pretty easy to wire (lots of how-to’s on the internet). I bought a heating pad from Williams Brewing that just sticks to the wall of the fridge. You could probably do the same thing with a cheap heating pad and some velcro or double-sided tape for cheaper (the pad was $30 IIRC). With the single stage Ranco, you don’t need to move any pins, just select cool or heat in the regular controls.

I built a temp controller using a cheap aquarium temp controller and it works great.
I wired it to a cold and hot plug. The top plug controles the fridge and the bottom one controles a 50watt bulb that I hung in the fridge. Once the fridge gets to temp the fridge and bulb seldomly turn on.
Here is a quick link to the video i followed. It was pretty simple. Total cost: About $35.

Thank you all, this is great info.