Another fermentation fridge question... which heater?

[lahoski]

So I brew small batches fermenting in demijohns. I have a small tabletop freezer I intend to use as a fermentation chamber - I can fit two demijohns in so it's pretty much perfect.

I need to find a solution for heating... the space in the freezer has the following dims in mm (HxWxD)
150 x 340 x 140
I want to find something that provides sufficient wattage without risking scorching the top/walls of the freezer.

Would a tube heater be okay if it is small enough? Or would some kind of fancy arrangement of a heat cable be better? I'm guessing for that kind of volume I'm only looking at a v low wattage requirment (maybe ~10W)?

One thought is that I might try a method of souring that requires culturing lactobacillus from yogurt - so it needs to be able to heat the chamber to approx 40*C if possible...

 

[Sbond10]

Or a ceramic bulb holder and infra red ceramic bulb. That's what's in mine

 

[Fil]

dip a low wattage incandescant light bulb im mat black paint perhaps?

motorcycle handgrip heating pads are basically 6" square film heat radiators that run off dc voltage

or you can source heating flex for heating reptile enclosures that you could tape to the freezer walls..

one thing you dont mention is a fan?

as the air contained in the freezer is the medium of heat exchange between the heating and cooling and your demijons of valuable beer moving it around with a fan will improve the efficiency no end.

a small pc dc voltage fan powered by a redundant phone charger is ideal.

run the fan 24/7 when using the brewfridge.

if you buy a commercial fridge or a high end domestic fridge you will invariably find a fan inside :)