After playing a lot with my spreadsheet, i think the best compromise is to test a full range of target temperatures (0 / -5 / -10 / -15), and to find at wich power the cooler is stabilizing.
After, (this is what i'm trying now), you can set Cstart to -5% of this value, and Cmax at +5%
Example : i've found that to reach DT=-30, my cooler is stabilizing around 50%. So i set CStart to 40/45% and Cmax to 55/60%. Then i set Kp to 0.08
This way, the "cooldown phase" is faster, and i don't overshoot too much
What do you think ?
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