A custom here in Minnesota is to dangle a light bulb near the water meter or any other water-carrying pipes that are in your unheated basement. You don’t need a switch. You just have a light socket on a wire, and at the beginning of winter you screw in a 100 watt light bulb, and at the end of winter, you loosen the light bulb so it stays off for the summer. This prevents the pipes from freezing and provides light in the basement at the same time.
This sort of practice has led me to wonder if compact fluorescents should be pulled out of some of the light sockets during the winter, and replaced with incandescent, because, after all, they are generating heat. I’ve wondered if this is in any way efficient.
Well, it turns out that it probably isn’t assuming you are heating your house with natural gas, and have a reasonably efficient furnace. How do I know this? By reading a blog post called Compact Paradox over at Thinking for Free.