I recently made the switch to using a thermowell with my wine-fridge fermentation chamber and have noticed large swings in temperature due to the slower response of the probe in the thermowell compared to being strapped to the outside of the fermenter. Currently I use an ITC-308 which lets you set the temperature +/- 1ºF. Are there any two-stage temperature controller options that are more precise? Ideally I would be able to set the temperature +/-0.5ºF or less. Thanks!
Higher precision temperature controller?
- Thread starter zman_
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Thermal grease.
broadbill
Well-Known Member
Why do you need +/-0.5F exactly?
zman_
Well-Known Member
Since I am measuring the "core" temperature of the beer I can control it more precisely without excessive cycling of the compressor/heater. Basically the temp lag introduced by the insulating beer/liquid means that more precise control is possible.
zman_
Well-Known Member
I fail to see how this would help? The probe is accurately measuring the temperature, it's just that the +/-1F at the core of the beer is more St the edge of the beer/etc, and the lag from the insulating beer means that I over/undershoot the temp on each cycle
hopsandhops
Well-Known Member
A BrewPi will do this for you. It uses a PID algorithm to predict and prevent those wort temp swings, based on the ambient fridge temp. There's a thread on here to build one yourself, if you're up for that. Google "HOW TO BrewPi cheap" or something along those lines. I built one to control my wine fridge chamber and I love it. I started with and stc-1000 before wanting something more precise
broadbill
Well-Known Member
Wouldn't tightening up of the allowed temperature range result in more cycling of compressor/heater?
zman_
Well-Known Member
It would increase the cycling, but reduce the temp swings of the beer. Right now the thermal lag is so that the long cooling cycle may cause the heat to kick in and a long heating cycle may cause the cooling to kick in. Reducing the threshold for cooling and heating would fix that
broadbill
Well-Known Member
How much overshoot do you get now, and how much are you trying to prevent? Decreasing your temp range on the controller is a bit a a brute-force approach to control this, and you may not even be that effective.
+1 to the algorithm-based approach. Personally, I think this is too much like work for something that doesn't matter that much, but to each their own.
zman_
Well-Known Member
It would overshoot the desired 67ºF up to 69-69.5 while heating, I haven't monitored it while cooling. I am not married to the idea of having a narrower range on a temp controller, just looking for a method that would provide better temp control/minimize swings and reducing the temp range was the first thing that came to mind.
broadbill
Well-Known Member
I dunno, +/- 2 to 2.5F is pretty darn good considering the system. Recirculation would help but that isn't an option for fermenting beer.
I can't see how a 67 SP/69.5 PV would make a measurable difference in the final product.
d3track
Are you sure about that?
what is your heat source
zman_
Well-Known Member
+/-2.5ºF in the middle of the beer could be indicative of much greater swings at the fringes. Obviously, I will need to see how this batch turns out to see if it had any impact (positive or negative) on the product. Making/buying a brewpi seems to be a reasonable option and I should be able to pull it off since I have a bit of background in circuit design/electronics (although not much).
The heat comes from a 50watt heat cable that I have draped around inside the fridge.
broadbill
Well-Known Member
My bet will be that you will be making good beer. I don't think this process is eafected significantly by 2.5F temp swings.
+1 on the BrewPi. It is by far the best choice available for tightly controlling temperatures. Plus you get logging, and ramping capability.
Brew on
Brew on
