On Sunday I made myself a temporary warming cabinet for a 20 litre bucket of set honey.
I started looking at old fridges/freezers on facebook marketplace then realised I already had everything I needed.
I didn't really want to buy/store more kit so I have just built something temporary out of spare parts.
If I was starting from scratch and buying stuff then I would not use such expensive components.
Ingredients:
1 14x12 poly brood box
1 poly super
1 wooden/metal roof (I wish that I had a spare poly one)
1 460x460 plywood square for the floor
2 short lengths of timber to put the bucket on so that it is not resting on the floor
1 30 watt soil warming mat
1 old PC fan to circulate air
1 cannibalised 12V power supply for the fan
1 raspberry pi
1 DHT22 temperature sensor
1 240 volt relay
various electrical wires/sockets
The interesting bit for me was controlling the whole thing on the raspberry pi using
Node-RED.
View attachment 30720
The soil warming mat is powered through the 240V relay.
The pi reads the temperature sensor every 5 minutes. If the temperature is above 39°C then it sets the relay to off, otherwise it is set to on.
The cool thing about node-red, is it makes it very easy to create a web based dashboard. So now I can see a chart of the temperature over the last 2 days. You can see dips where I checked the honey.
View attachment 30721
I found it really interesting how much heat was leaking through the wooden roof, the 30 watt mat did not seem sufficient to keep it up to temperature, I did not have any spare kingspan/celotex. So now I have wrapped the whole thing in a blanket and an old duvet and stacked some sofa cushions on top.
Its nearly done, and when its finished I can put all the components back to their original use.