PHOENIX - Hot weather is already here, and the annual argument over whether your thermostat should be set at one temperature or fluctuate during the day isn't far off.

But does it actually make sense to change your thermostat settings throughout the day? Or should you pick a temperature and leave it?

"Set it and forget it," Mike Donley of Donley Service Center said. Donley owns an air conditioning repair business and said changing the thermostat, so that it's warmer when you're not home, could actually cost you money.

"If the house warms up," Donley said, "you're going to use more energy than you saved by turning it off."

Plus, Donley said, that setting fluctuating temperatures could increase wear and tear on your A/C unit.

But utility company Salt River Project, says it is possible to save money by picking a payment plan that identifies peak hours.

If you "pre-chill" your house by an extra three degrees before the peak hours begin, SRP says you can set your thermostat higher during those hours.

That way, it's not unbearably warm when your air conditioner turns back on after peak hours are over.

So according to the experts, both methods work, depending on how you do them. But they also warn, both methods depend on how energy efficient your home and air conditioning unit are, as well as how comfortable you want to be.