2017 (Glycol) Tank, Pump, Chiller, and Heater setup


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. :smiley:

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?



Hmm your setup is a bit different from mine. I have a heating pad on the fermenter.
This makes the hole thing a bit simpler:

  • The glycol is kept cool and the pump runs when cooling is needed
  • The heating pad runs when heating is needed.

Even in your case, I think you’ll want a slightly different algorithm.
During your brewing process, you’ll be either heating or cooling. Rarely you need both.

So I would keep, for example, the water 5 or 10 degrees above or below the beer temp. Then run the pump to manage temp.

This is not possible with the current BrewPi software yet, but I can think of ways to implement it.

I doubt however that a single bath to do both is the best approach. I’d say that a separate source of hot and cold water would be easier to work with.


Thanks, Elco. I’m going to pick up a heating pad and try that technique out on the next round through. Actively heating and cooling the water has worked really well given the environment I’m dealing with here, so I think it’s a worthwhile setup in general, but I think getting all of the bells and whistles of BrewPi going is worth the investment in a heating pad, too.

I really appreciate your response!