A friend of mine recently asked me how it’s possible that a 5% change in the thermostat can result in a 12.5% savings in your fuel bill. He felt like the math didn’t work. Here’s why it does:

If it’s 25 degrees outside today, and you keep your house at 65 degrees, then you’re heating up 40 degrees. If you turn the thermostat down 5 degrees, it’s not 5/65=7.6%, but rather 5/40=12.5%

So turn that thermostat down and save some money!