Would a reptile heat mat be suitable? Keeps my beer to within 0.3c on the garage I have fridge but I don't ferment in it and don't have enough height for a tube heater.
you dont have to sit the heater below the brew IF you employ fans to keep the air inside moving as thats the medium of exchange. so as long as air is moving it will move the temperature differences off the hot and cold radiators and transfer it to the brew..
And any gentle heat source will work, it needent be a tube radiator, the ceramic bulb reptile heaters can be a bit strong and melt the inner shell if positioned too close but folk use em happily enough
My brewfridge base fridge was ebayed -no photos.. didnt arrive exactly as expected.. simply it was too small width wise for my brewbuckets
never mind i switched to FV's that will fit inside 25l no-chill jerrycans and with about 1/2 a centimeter clearance i can only just squeeze a 4" neck fermentor in..
The heater i needed to sit at the top otherwise it would have been radiating heat a centimeter or so away from the brew vessels wall ..
the result works a treat however even if not quite as i intended when clicking the buy it buttons.,.
it was advertised as a Fosters bottle fridge, Fosters being a brand of top end commercial SS fridge and freezers, this thing arrived with a powder coated mild steel case plastered with fosters brand lager promo stickers! DOH!!
tho with the features sorted its worked out quite nice, the 2 x 2foot light tubes and glass door allow an easy spy on the brew without opening the door and upsetting the internal temp..