Weekend DIY Homebrew Project: Dual Stage Temperature Controller STC-1000
You rigged up a dual-stage temperature controller so you could both heat and cool. The cooling part is relatively simple but what is the best way to heat and also measure temperature?
I picked up the cheapest, lowest powered hair dryer I could find at Wal-mart that is very similar to this one. I basically (carefully) screwed an S-hook into the top of the fridge to hang it from so that it can gently blow warm air around until temperature is reached. I wanted something low-watt from a safety perspective yet could get the entire chamber up to temperature relatively quickly. So it is suspended away from the carboy and isn’t near any of the plastic walls.
You may also wonder where to place the temperature probe. I’ve had good luck taping it to the side of the carboy with a small layer of bubble wrap on top so it is less sensitive to fluctuations in the air temperature. You should also expect the internal carboy fermentation temperature to be a degree or two higher than what the probe registers. You can also consider investing in a thermowell that allows you to insert your probe into the fermenting wort for a more accurate reading.
I also set my temperature sensitivity to 1.0°C and set my compressor delay to 10 minutes to avoid burning out my old garage fridge. So far, this has worked pretty well for me but you may want to monitor it closely if you experience extreme temperature swings (like I do in my garage).
Best of luck and don’t be intimidated by this project! It’s actually pretty easy if you take the time to watch the videos and ensure you have all the necessary parts.