Using room temp as input for PID when using a conical, no fridge


#1

I have a SS conical, with a glycol chiller coil inside it, and a neoprene wrap with a heating blanket in the cone (the Spike Brewing 10gal setup, but that doesn’t matter for this)
I’ve got a glycol chilling loop for the chilling coil, and I’ve got the heat blanket for some measure of heating. I tested it, at full power the heater can raise the temp of 10 gallons of beer 1.3 degrees over the course of an hour. The outside air temp is about 10 deg colder than the beer, so right now the conical is just outside my door on the un-heated common area, so I’m just using the heater.

I was wondering if i can feed the “room temp” reading into the PID loop, to give it extra information about how much heating it needs, as the temp of the room changes.


#2

When using direct heating and cooling of the conical, it works best if you don’t set up a fridge sensor and only use the beer temp sensor. The PID will then use the beer temp as input directly.

You can still use log 1, log 2 and log 3 for just logging.

Room temp does not exist in the latest version of the Spark firmware. If you are using Arduino, the firmware really was not designed for this setup and it contains minimum heating and cooling times that don’t work well with a glycol loop.

When we release the new BrewBlox firmware, you have a lot more freedom to create your own control schemes on the Spark.

So if you are using the Spark, update the firmware to 0.5.10 and remove the fridge sensor. If you are using the Arduino, upgrade to the Spark. The Arduino version doesn’t have PWM, which is a must with your setup.


#3

Ok, I don’t have a fridge sensor setup, and I do have the newest version of brewpi, updated to the most recent firmware. Thank you!