Conical with Glycol and Fermwrap Settings

Hi - I’m running a glycol loop with a small pump and fermwrap for heating. I started my fermentation with a free rise (heater disabled), and then enabled the heater once I reached my desired fermentation temp, which held well. After a couple of days I ramped from 66 F to 71 F, but the swings are much larger. Any suggestions?

Here are my settings and plot:

Beer to Fridge: Kp=0, Ti=0 Td=0
Max diff between fridge/beer set point=18
Beer to fridge input filter delay 18s
Beer to fridge derivative delay 159s

Cooler Kp=10, Ti=1800, Td=200
Cooler PWM 600, Min off 10, Min on 5
Cooler input filter delay 18s
Cooler Deriv filter delay 159s

Heater Kp=30, Ti=7200, Td=120
PWM=4
Heater input filter delay 18s
Heater Deriv filter delay 159s

Thanks for any suggestions.

What’s your heater power?

I think you’ll need to be more gentle with the glycol (Kp = 3, Ti = 14400, Td= 60) and more aggressive with the heater (Kp = 100, Ti=14400, Td = 60). Set your dead time to 2 hours (7200).

Thanks - I’ll give it a shot.