With temps in the mid 90's this week, most of us are running our AC around the clock.  This common myth about air conditioners might have cost you.

Some people say that if you want to save money, you should leave your air conditioner on low when you're not home, because it requires more energy to cool down a hot room than it does to keep a room cool.

But according to the American Council for an Energy-Efficient Economy, that's not actually true.  In reality, air conditioners are most efficient when they're running at full blast.  So in other words, turn your air conditioner off when you leave for work, then crank it to cool your place down as soon as you get home.

If you have central air, you should either turn it off or set the thermostat at 78 degrees or higher.  Each degree above that saves you about 3 to 5%, meaning that if you set it at 80 instead of 78, you're using up to 10% less energy.

If you're any good at math, this might make sense... but I find that if I don't KEEP my house cool during the hottest months, it takes several hours to get things under control when I get home,  especially the upstairs.

(Rodale)