Temperature Controller/Fridge Operation Question

[blugrazz]

Hopefully this is simple. When using a temperature controller on a fridge for a fermentation chamber is there a perferred setting for the fridge's internal temperature setting (i.e. coldest or warmest)? Are there any advantages either way? I would assume a fridge doesn't provide any colder air amongst those settings but just works longer to achieve colder temperatures. Also, is there anyway to turn of the freezer portion? I do not see any obvious control but is there a manual switch or relay on the compressor, etc.

This is typical kitchen fridge/freezer about 20 years old.

 

[theveganbrewer]

I find that somewhere in the middle works best for me. I am probably just imagining this or making it up, but I think if it's on the highest setting (strongest) that it will overshoot the desired temp before it shuts itself off.

On the freezer, it's on the same unit, so you'll have to set it to "defrost". Not sure if you have one, but if it's just a dial, turn it to defrost. If there is some sort of screw calibration, turn it clockwise until the compressor turns off.

 

[Curtis2010]

The internal thermostat must be set to a colder temp than your external thermostat. Otherwise it will turn the fridge off before it reaches the external thermostat's set-point.

 

[blugrazz]

Thanks guys. I don't recall seeing a defrost setting but let me look again.

 

[Kingfish]

Thanks guys. I don't recall seeing a defrost setting but let me look again.

You would not want to use it anyway....Defrost activates a heater. Just set it to max and your external controller will take care of it.

 

[billl]

Just FYI on fridge functioning. The compressor is either on or off. It doesn't have a high, medium, low etc. The dial in the fridge just controls the temp at which it the compressor cuts on/off. Since you don't want the fridge to be making those decisions anymore, just set it to the coldest setting so it never sends a signal to cut off the compressor. That way, as far as the fridge knows, it is always "on" and then you are free to control the temp externally.

Of course, none if this matters at ale temps, but it could come into play if you crash cooling a batch or lagering.

 

[Tarheeltransplant]

Just FYI on fridge functioning. The compressor is either on or off. It doesn't have a high, medium, low etc. The dial in the fridge just controls the temp at which it the compressor cuts on/off. Since you don't want the fridge to be making those decisions anymore, just set it to the coldest setting so it never sends a signal to cut off the compressor. That way, as far as the fridge knows, it is always "on" and then you are free to control the temp externally.

Of course, none if this matters at ale temps, but it could come into play if you crash cooling a batch or lagering.

Thank you Bill, i have had the analog johnson control on my fermentor fridge for about a year. I am cold crashing for the first time after fermenting my first 2 lagers for several weeks. Been nervious about the fridge cutting off before it reaches 34 F. Thanks for your help.