I can't find the thread for using a light bulb/ heat light and a regular thermostat to heat a fermentation chamber. Can anyone post the link?
Here is a link. Convert a thermostat
But keep in mind the thermostat will need control a relay if using a common 120V AC heat source since home thermostats are built to switch 12 - 24V DC.
Here is a cheaper, more efficient way to do it (assuming you aren't fermenting in a really cold area, just a cool one):http://www.homebrewtalk.com/f39/idea...ml#post1654503