Converting a fridge for fermenting beer

Step 7 Heating

During the warmer months when the ambient temperature is higher than the desired fermentation temperature, the fridge will do the cooling.  During the colder months I need some way to heat the chamber.  I used a cheap $1 ceramic light fixture, and mounted it on a scrap of 3/4" MDF.  I siliconed all the seams to make it as water tight as possible, and then made some feet to lift it off the bottom surface using screws.  This is just in case I have an overflowing fermenter or exploding bottle.  I then bought a ceramic infrared light bulb from a pet store.  They're normally used to heat terrariums for snakes and lizards.  When temperatures drop, I simply place the heat bulb under the shelf, and then plug it into my temperature controller.  The only disadvantage is that I can't fit as many bottles under the shelf to bottle condition during the colder months.