I use a refrigerator with a temperature controller to keep my fermentations cool, but during the winter, the basement can get too cold for proper fermentation temperature for some ales. For less than $30 I came up with a solution. It's the legendary, multi-use, Ice Cube cooler, an aquarium heater, and a fountain pump. The heater is a 100 watt heater with a thermostat that ranges from 66 to 86 degress F. I got it at a pet store for around $22. The 66 degrees should be low enough for most ales, and you can get it high enough for the Belgian styles that require higher temperatures. The pump is from Harbor Freight, and is used to keep the warm water circulating to prevent temperature stratification. I think it was on sale for $5 or less.