Converting old fridge into ferment chamber

A buddy of mine just gave me an old Full-size fridge/freezer combo, the kind that the bottom 3/4 is refrigerator and the top 1/4 freezer. I plan on converting the fridge portion into a ferment chamber by simply adding a Johnson Controls Temp Controller and building out the interior of the fridge to hold the FV's better.

My questions: Will I run into problems with temp control because of the freezer above? Do I need to turn the freezer portion off? Is is possible to still use the freezer and just have the temp controller run the fridge portion?

Thanks

In for answers.

I use the top-freezer style fridge as my fermentation chamber. How mine works, the cold air is blown into the freezer portion of the fridge. The cold air descends to the refrigerator portion through two vents in the freezer. In this design, there is no turning off the freezer portion (there's only one cooling device). The freezer remains colder than the fridge, but probably not cold enough to safely store food. That is, unless I'm fermenting a lager or crash cooling my beer. I have a battery operated digital thermometer to assist in gauging temperature. I like this setup, it works great for me. I can fit two carboys at a time. I've removed all the shelves except the bottom shelf and I support the weight of the carboys from underneath that. I keep the temperature setting of the fridge set to the coldest setting possible which seems to keep the temperature in a 2-4 degree range and probably helps the fridge operate for less time.

Also, about the Johnson controls. Mine works, but the dial is pretty much useless. I use the battery powered thermometer to assist in dialing in the correct temperature. For instance, I know with my setup that setting the dial to 62 will keep the actual temperature at 68. I've read others have this issue. It might just be b/c I bought the inexpensive controller, idk.

Hope this helps.

Thanks for the reply.

Sounds exactly like the fridge I have. Must be pretty common for the cooling to go to the freezer then to the fridge with only one cooling element. I am shooting for the same set up you have, remove all shelves and support the bottom shelf with some bracing.

Any ideas what to use the freezer compartment for? Hops/yeast storage, bottled beers? Sounds like it might not be cold enough for that.

What would you estimate the temp of the freezer to be if you have your fridge set at say 55F? Roughly

Make it as cold as possible and use a brew belt or FermWrap to heat the fermentor, that way you can lager and ferment in there.

CrackShotHolmes said:

What would you estimate the temp of the freezer to be if you have your fridge set at say 55F? Roughly

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On my fridge, the freezer stays about 30 degrees F colder than the refrigerator, plus or minus a few degrees.

Being that you're in Michigan, you might want to consider a dual stage temperature controller, depending on the location and ambient temperature where the fridge is to be located. Even where I like in North Florida, I could use one during the winter. That's an upgrade I plan for next season.

Hope this helps, let us know how your setup turns out. Having a well controlled fermentation chamber is awesome.

I was debating whether to get a dual stage temp controller or just switch out the fridge plug for a heating element (light bulb, reptile heater) when temps drop in early winter and then switch them back in late winter when temps rise. It might be easier to just get the dual stage and not monkey with switching from cold to heat???

Or pickup one of the STC1000 controllers on eBay for $25 and have 2 controllers. I have 2 and they work great, they display in Centigrade.