Guide to buy hardware

Hi guys,
Sorry - I am totally newbe here. But I want to build a solution which can control heating and cooling for my two new fermenters and came across Spark 4 and think this is the solution.

I have read a lot of posts but I’m still not sure what hardware to order.
Could someone please help me out?

My request goes like this:

I have two new jacketed unitanks with thermowells. Fermenters are mounted with 500 w. 230 V AC heating elements Heating Element, 2" 500W 230V, EU For Unitanks etc, Schuko(EU) Plug - Brewtools EU.

For cooling I use a glycol chiller with a submerged pump for each fermenter. Pumps are also 230 V AC. Teichpumpe 1500-3000L/h Garten Koi Springbrunnen Aquarium Tauchpumpe Super ECO | eBay

Currently I use an Inkbird 308 Wifi for each device (chiller and the two fermenters) but I have issues when I want to cold crash beer in one tank and hold the other one at e.g. 19 degrees. Then I get an overshoot in cooling in the tank with 19 degrees. And also overshoot challengens when heating.

As I understand from reading on the homepage and also in the this forum I can solve the issues with a Spark 4 and a Raspberry PI. But unfortunately I have no clue what else to order. Of cause some temperature sensors and I gues also some relays?

Ideally the equipment can be wall mounted on a Din rail on the wall. Second priority is in a box on the wall.

For output to the pumps, heating elements and the glycol chiller I want to use something like this: Finder stikdåse Schuko til DIN skinne m/LED, 5 stk | 07.99.00 |

If it makes any big difference pricewise I can use one of my old Inkbird controllers for controlling the chiller and then only Spark for pump and heating elements to the fermenters.

I would appreciate details - what can I buy in the BrewPi shop and what do I have to buy somewhere else?

Feel free to ask for more details.

Best regards and thanks a lot,

Claus Lücking.

As you already have the heating elements, pumps, and chiller, you’ll need

If your tanks are next to each other, a single spark can control both. The maximum distance is mostly due to the sensor cables. OneWire cables longer than ~3m are very susceptible to interference.

At minimum, you’ll need two sensors (one per tank), but you can add more sensors to track room temp, chiller temp, or to get an averaged value of multiple sensors per tank.

For the Spark, a single GPIO module normally controls up to 4 SSRs (although you can wire it to squeeze in 3-4 more), and 4 sensors. If you need more than that, you can attach up to 4 GPIO modules to a Spark.

The Spark can be ordered with DIN mounting brackets. Enclosures with DIN brackets are available for the Pi (but are not sold by us).

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Thank you - just what I needed!

I will have everything close to the Spark but maybe buy the sensors with the extra long cable anyway.

If I understand correctly I can buy one more SSR and one more temp probe and also let the Spark control the chiller?
And is it possible to let this extra probe in the chiller influence the temp controlling of the fermenters so this depends both on the temp in the tank and the temperature of the cooling liquid? Or maybe I need two probes in the chiller for this if it is possible at all?

Can the heat sink parts also be DIN rack mounted in a way?

Thanks again,



Technically you can do this, but it will make configuration significantly more complicated for very little gain. It’s best to set the chiller to a specific temperature, and then tune the tank cooler accordingly.

Yes. The heat sinks don’t get very hot, and compatible DIN rail clips exist (but are not sold by us).

Thanks again. Now I fully understand the need for hardware.

But before I pull the trigger I want to be sure this setup will cover my needs. (A bit hard to explain but I try…):
When I have configured the software I will be able to enter a desired temperature for each tank and the controller will then control pump and heating element for each tank in a way so I don’t get high overshot in temperature?
By this I mean that e.g. I’m coming from 25 degrees for the wort in the tank and set the temperature to 19 degrees and the cooling liquid is 5 degrees - the pump with cooling liquid will have some longer and longer stops before the liquid in the tank reach 19 degrees eventually?
And in this way I will have a better control than from what I currently have using an Inkbird 308 which just stops at the set temperature and give overshot then.

Exactly how it works. For glycol the wizard sets up a 10 min PWM period with a low PID gain. That means that if you get close to the setpoint, you’ll only get a 5 or 10 second burst of cooling every 10 minutes.
Glycol cooling is very powerful, so you need only small puffs of cooling.

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