fermentation control

[Megastout]

For those of you that use a freezer or fridge as a fermentation chamber with a controller, I need some help.
I have had a freezer in the past and recently a fridge go down the tubes. Don't want to keep buying units that have a short life because of a poor controller. Presently have used a johnson analog controller.
Any thoughts about other controllers that don't hasten the life of the fridge/freezer.
Thoughts and experience would be most helpful.
Thanks

[JonW]

If the freezer/fridges are dying quick, I'd venture to say that the units are short cycling which is killing the compressor. How are you measuring the temperature? Do you have the probe in the air or is it in the liquid? Air measurement is prone to fluctuations that can erroneously trigger the fridge/freezer to kick on/off too often. Ideally, you'd use a temp probe that is submerged in the wort via a thermowell.

It was a lot of years ago that I used a Johnson controller and I don't recall if it had any kind of short cycle protection. Which model Johnson are you using?

Some temp controllers are PID controlled which can also cause issues with fridge/freezers that don't like quick on/off transitions. I personally use the BCS units that give a hysteresis control and also let you set a differential so that you don't short cycle.

[Megastout]

Thanks Jon
The probe is in the air.
The thermowell I can do easily, will institute that measure.
The existing controller has no short cycle protection.
Obviously, was looking at changing the controller.
Williams bros shows one called the Keg King Dual Controller which includes "an adjustable differential, adjustable delay between the start of cooling and heating". Your thoughts?
Thanks

[JonW]

The specs on that controller look like it would work just fine. A few more features than the Johnson. Many use the Johnson just fine also and I would probably attribute your dying units to short cycling due to measuring air.

Have you done any troubleshooting on your dead fridge to see if it is just the relay or start capacitor that are bad? It's possible your units could be salvageable.

[gromitdj]

I'm a big believer in the BrewPi setup. If you are handy enough, you can build one for about the same price as the Keg King controller. During fermentation, my fridge comes on once or twice an hour.

You know where I live; so if you ever want to come look at my setup, let me know.

[Megastout]

thanks all!

[Megastout]

Jon
The fridge comes on, but will cool only to 74-75 degrees

[SamIam]

Maybe you just brew too much.

[maltbarley]

When I'm not using a thermowell in the wort, I put the thermowell in a jar of water to prevent excessive cycling. Conversely, in my fridge with an air probe , I set a high temp differential for the same reason

[lexuschris]

My first fermentation freezer went belly-up after 2 years... way too early, and all the suggestions above were the things I was NOT doing. Lesson learned!

I am still using the A419 Johnson Controller.


Now, I do have a gallon jug of water with its own thermowell in the lid, so I can put the probe in there when not fermenting. I also change the 'differential' to at least 5 degrees during these times. Thus, the gallon jug must raise 5+ degrees before it cycles on to chill down to temp. During fermentations, the differential is set to 1.

That unit also has a setting for a maximum # of minutes before it could cycle back on, to help prevent frequent short cycles. I think I have that set to 5 or 10 minutes.

I've been looking at some of the other units on the market, and for that $70-$90 price range, there are many choices.

In the 'overkill' category is the Fermostat from Ohmbrew.
Great if you really want to measure & control everything, but twice the cost!

Good luck!
--LexusChris

[Megastout]

Thanks Chris

[dhempy]

Just saw this link on HomeBrew talk ... sadly they don't list the BCS series as an option even though the Brew-Pi is.

Dan

[Megastout]

Thanks everyone on line and at yesterday's meeting enlightening me on temp control sensor use.
I was bad mouthing my controller, but I now know it was my ignorance of the sensor application.
I obtained a Thermowell and will keep the sensor in liquid, wort or water, not in air. And, maybe my fermentation fridge will live longer.