This is a follow-up topic to New Setup for Glycol Tank + Pump and New Glycol A/C setup - New to BrewPI too to ask about 2017 / new API status, since it’s been a year and a bunch of cool updates later than the earlier thread.
I’ve got a system right now with some super-basic controls that looks like this, which handles my desert shed’s extreme temperature swings:
Basically, I’ve a heated and cooled exchanger hooked up to the fermenter with small closed-loop recirculating pump putting distilled water through the fermenter-side of the BrewTech FTSs, but with my own little Arduino controller handling the OneWire temp probes and relays. The chiller is a hacked up freezer, and the heater is 100W coil, both submerged in distilled water.
I’d love to swap to a BrewPi Spark3 to get the nice analytics and make the install look professional instead of … what it looks like now.
It’s pretty easy to see how to set up a control algorithm to trigger the heater or trigger the chiller, but I also need to control the recirc pump. Electrically, I can just make the pump run whenever the heater or cooler are commanded to activate, and could thus use this setup with the BrewPi, but that’s not going to be the most efficient. Right now I have the recirc pump only run when the water temp gets close to what I want the beer temp to be. So the general algorithm I’m using is something like this when flattened:
if (waterTemp is diverging from targetTemp) enable the heater or chiller as appropriate if (beerTemp is diverging from waterTemp) enable the pump
So the question is, I suppose: Is the control loop configurable enough these days to handle something approximating this, or would I need to go electrical here?