StillSmart

After some research it seems these are just the same as this beasty I have on my stove.

https://www.gyroscope.com/d.asp?product=ECOFAN2

The difference in temperature of the two surfaces causes a thermoelectric change. The peltier effect.

But it does beg the question if fermentation cooling is really a requirement in the UK

I think with the correct insulation
ie celotex, temp should remain stable.

I think it does have a peltier element inside, if you look at the photos, there are three wires of red and black, two of each for the fans and the second will be for the peltier element.

Interestingly reversing the polarity to a peltier element can cause it to cool or heat, it could be an all in one solution for heating and cooling, a relay could be used to reverse the polarity when it gets too cool to make it heat and vice versa, I feel a bit of research into my very faded knowledge of peltier elements is needed.