I keep my smaller fermentation chambers (aka converted dorm fridges) in the basement and with the winter we’ve been having, it’s a cool 60 degF. Needing warmer temps for my ale fermentations, I had to whip up a heater.
I used a green bean can, a tomato paste can, a candelabra bulb base, a lamp cord and some extra’s.
Dorm fridge = not much space available, so here is what I came up with:
I agree that the light is an undesirable byproduct of heating a fermentor this way. Seems like you could cover the can with an opaque lid but I’m not sure if that prevents the heat from adequately escaping the can or would make it too hot in the can to be safe to use.
If you could rig up a baffled multilayer cover it would allow air flow without light flow. two layers with alternating vents that didn’t overlap at all would do it.
I’ve seen folks wrap a bulb in foil. Honestly, the whole incandescent lamp in a can has made me nervous. I opted for the reptile heater as it is designed for that use, at least sort of designed for that use.
I think the baffle on the top is a good idea, so I might try something later. I’ve only used it for a while, but with the low 25W bulb I’ve got in there doesn’t get “hot”. I’ve still been able to touch the metal can. It’s really just a warmer. The coldest my basement gets is 60 degF, so I’m only needing to raise it 10 degF. If I needed more, I’d honestly spring for one of the heating pads.
Also, comments on a larger can. My constraints were that I needed a small can due to using it in a dorm fridge.
I use one of these. Works great. About $15 on ebay to my door. They last a long time. With my shop hitting 20º at night I can hold 68º no problem. When I do sours (lacto start) I add a second one that stays on all the time, and can hold 98º no problem
I did that for a few years until the hair-dyer bit it. Now I use one of these. It’s small, and on low wont melt anything, and most importantly has a fan for active air movement.
I use a Repti-Heat cable strung around the chamber with the outdoor Command hooks. The cable is made for direct contact in terrariums, so it doesn’t get too hot for the hooks (which are rated up to 120F).
Personally I use the equivalent of fermwrap that is designed for use with reptile tanks. It’s cheaper than fermwrap and more durable than the old brew belts. Wrapping a fermentor in it and placed in a dorm fridge allows me to get over 100F in there. It could be hooked up to a temperature controller and hung or loosely wrapped around a fermentor to keep closer to room temperatures.
Take a look at the products here: http://www.reptilebasics.com/heating. That’s where I bought the reptile tape I use but they have other products that might work better for your particular purpose.