Top freezer fridge control

[kerklein2]

So I've received an old top freezer fridge for free that I plan to use for fermentation. I had hoped to be able to maintain freezing temps in the freezer while fermenting in the bottom by hacking the controls for it. I've got it all torn apart and discovered the control system for blowing cold air into the fridge section is entirely passive. A knob labeled "freezer temp" manually closes and opens a damper for cold air into the freezer. Warm air return to the evaporator in the freezer is just open. "Fridge temp" controls the relay to turn the compressor and evaporator fan on/off based on a temp sensor in the fridge.

This all seems pretty squirrely to me, but my conclusion is that I can:

A. Turn the freezer control to "coldest" (close the cold air damper into the fridge), control the fridge power with a Ranco or similar, and hope for the best.

B. Get real fancy and control the freezer with one controller, then use a PID controller to control a servo motor hacked on to the damper control while also sealing up the damper (it currently still allows air even all the way closed).

Anyone have any other ideas?

 

[BigFloyd]

Get a small chest freezer for freezing and use the fridge (controlled by an STC-1000 or other) to ferment.

Because (as you have discovered) the fridge temp dial is simply an air balance damper adjustment and the single compressor chills the freezer, you cannot do both accurately with the same unit.

 

[kerklein2]

Not really looking to freeze accurately, just be below freezing. I'm up to 5 fridges in the house at this point, so I'm not looking to add another.

 

[joeg13]

I use a fermwrap controlled by a Johnson Controller on my carboy. I put my carboy with the wrap in a carboy parka. I let the fridge run normally. Works perfect.!

I have admit I borrowed the idea from another forum user.

 

[kerklein2]

I use a fermwrap controlled by a Johnson Controller on my carboy. I put my carboy with the wrap in a carboy parka. I let the fridge run normally. Works perfect.!

I have admit I borrowed the idea from another forum user.

Interesting idea.

 

[joeg13]

Here's a thread with pics of the same setup.

http://www.thebrewingnetwork.com/forum/viewtopic.php?p=241177#p241177

 

[BigFloyd]

Not really looking to freeze accurately, just be below freezing. I'm up to 5 fridges in the house at this point, so I'm not looking to add another.

Next time my wife says anything about the three fridge/freezer units in our house dedicated to beer, I'm going to have to show her this post.

If accurate freezing isn't an issue, +1 on the fermwrap or reptile warmer pad regulated by a controller + parka.

 

[beaksnbeer]

That's how I keep mine I can still keep the freezer at 0* to -5* while the fresh food area(lagering) will hold 52*-42* respectively I replaced the oem control with a STC-1000 to control the freezer.

 

[kerklein2]

Next time my wife says anything about the three fridge/freezer units in our house dedicated to beer, I'm going to have to show her this post.

If accurate freezing isn't an issue, +1 on the fermwrap or reptile warmer pad regulated by a controller + parka.

To be fair, I included the kitchen fridge. 4 for beer.