RALEIGH, N.C. (WNCN) — Duke Energy says this is the most expensive time of the year for customers because we’re cranking the air conditioner more than ever, but there are ways to chip away at the costs.

It all starts with making sure you have a clean air filter.

Spokesperson Jeff Brooks tells CBS 17 dirty air filters can increase your cooling costs by around 20 percent and can make the unit work a lot harder.

He also suggests closing the blinds on the sunny side of your home.

“Your windows act like a greenhouse and can actually increase the temperature in your home and that makes your air conditioner work harder,” Brooks said.

Many of us like to keep our bedrooms cold while sleeping.

Duke Energy tells CBS 17 you can still do it but you’ll want to adjust your thermostat during the daytime.

“If you like it cold and that’s where you want to put it, think about keeping it cooler in the evenings but when the sun’s out in the day and everything’s working so hard, try bumping up your air conditioners a few degrees, especially if you’re going to be in the office or gone for the day,” Brooks said.

Duke Energy says you should also consider bumping up the temperatures by a couple of degrees because every two degrees saves you about 5 percent in cooling costs.

You can balance that out by running the ceiling fan in a counterclockwise direction.