STC-1000 Set Point Preferences

[brocasarea]

So, I've just wired up my STC-1000 for a ferment fridge with heating and cooling. It's an old upright freezer. Now I'm looking around for the best settings to avoid damaging the compressor etc.

I've read quite a few threads and there seems to be a variety of responses. From this search I've come up with:

Temp setting: 18°C (for now)
Difference set value: 1°C
Compressor delay: 3 minutes

Has anyone had a problem with similar settings?

I've also seen settings with comp delays of 10 minutes and difference values of 0.5°C. Any real value in setting them to these extremes?

 

[nosco]

Temp set will depend on what beer your making and how you are going to ferment it.

I have my difference set value at .5c so you only a 1c total difference in temp (and hopefully less over shoot).

I have my compressor delay at 10min. In practice it should be alot more than that anyway. Best to keep the compressor working as little as possible.

 

[brocasarea]

I have my difference set value at .5c so you only a 1c total difference in temp (and hopefully less over shoot).

I have my compressor delay at 10min. In practice it should be alot more than that anyway. Best to keep the compressor working as little as possible.

I guess they work largely hand-in-hand. Would I be correct in saying that 0.5°C difference and delay of 10 mins is largely the same as a 1°C difference and delay of say 5 mins? In terms of temp fluctuations and compressor on-time?

 

[nosco]

In practice the compressor delay doesn't really matter that much as there would be a lot longer delay than that in normal use bit it depends on your setup. I used to brew lagers (some successful enough) in a bar fridge in a garage that would be 35c+. The fridge would be running pretty flat out so any break would be good and the delay could be critical.

.5c on your ferment temp is more to do with the health of your yeast in the ferment. If you are running the fridge in a hot garage and you have it set to 1c leeway then the 18c set temp could be fluctuating from 18c+- to 19c+- a whole lot which isnt going to be ideal.
You are right in that you want to minimize the work on the fridge but keep the fermenter temp as constant as possible. It depends on your setup. Youd have to monitor a few brews to see how it runs. Its depends on the seasons/weather too.

 

[Danscraftbeer]

I think I set mine at 0.1c. Temp sensor into a thermowell in the kegmenter.
I don't think there is any way to reduce the work load of any chiller if you want real temp control is there? Other than keeping it shut.
It gets power cut offs via the temp controller rather than the chillers own thermostat. But it doesn't make any difference to the fridge/freezer does it? It may turn on and off faster sometimes or not at all for some times its great when you get that equilibrium.

Edit: I think I set mine at the lowest variable settings. Pretty sure, cant be farked checking but pretty sure.

 

[BrissyBrew]

I used to sell these units (actually Mashmaster paid the programming costs to the manufacture to unlock the temperature SET point range so they could be used for brewing). Two things which are important, probe placement inside the wort and you get greater overshoot in temps in a fridge but if you have a jacketed fermentor or you sit your fermenter inside a tub of glycol with a aquarium pump it works best, in the air where in the fridge can make a difference of a few degrees and up to 10*C in a chest freezer, a small computer fan to blow air around inside will fix this problem, best if you blow air directly on the fermenter obviously stainless is better conductor of heat than plastic or glass.

 

[Lionman]

I've also seen settings with comp delays of 10 minutes and difference values of 0.5°C. Any real value in setting them to these extremes?

This is what I use. The 10mins is so that the compressor in the fridge doesn't come on too often as it isnt good for it to stop-start all the time. It will wear out faster if it does.

The temp changes slowly anyway on the inside if you keep the fridge door closed. It takes a fair amount of energy to shift the temperature of 20+ litres of liquid.

I recommend you attach the temp probe to the side of the fermenter. Some thick gaffa tape or blue tack seem to work ok. I have a thermometer sticker on the side of my fermenter and t seems pretty close to what the temp controller is set too. I'm guessing at peak fermentation it might be a couple fo degrees warming in the centre of the wort, still well within the range of the yeast.

For heat, I just have a small 40w light bulb attached to the bottom of the middle shelf and a couple of computer fans that circulates air around. I can fit two fermenters in there but obviously can only measure the temp of one at a time.

I've been thinking of trying sticking the temp probe in a 1.25l bottle of water to get a sort of average temp, or getting some small digital thermometers that I can sterilise and put in the wort to gauge the relationship between the temp controllers reading and what the wort is actually doing.