Here are some of the most common air conditioning myths paired with the facts you need to keep cool and on-budget this summer.

Myth: Using an air conditioner will give you a cold.
Reality: Completely untrue, according to the AARP. While becoming chilled may make you more vulnerable to illness, the common cold is caused by a virus, not the temperature. Go ahead, turn on the AC—but keep your home clean and wash your hands often to keep those colds away.

Myth: It’s a waste of time and money to have your air conditioner serviced.
Reality: False. AC units need to breathe. Regular cleaning can keep your unit running smoothly and efficiently. It also provides an opportunity to catch problems that might have developed over the winter. Ignoring regular maintenance can mean an emergency call to the repair company on a weekend afternoon—with the extra charge that comes with it.

Myth: You can save money by turning the AC off or setting the thermostat extra high when you leave the house, then turning the thermostat down when you come home.
Reality: Untrue on both counts. When you come home to a hot house, the air conditioner has to work much harder to cool the place down. Turning the thermostat lower won’t help—most AC units only run at one speed, so a lower setting simply forces the machine to run longer.

Myth: It’s cheaper to leave the thermostat at the same temperature all day, even when you go to work.
Reality: Not true. Using a programmable thermostat can let the house warm up while you’re gone, then start cooling things down before you get home. This allows your unit to take a break when it doesn’t need to use energy.

Myth: You’ll be most comfortable if you just get the biggest air conditioner you can afford. After all, it’s just a big refrigerator, right?
Reality: Not right at all, according to the Arkansas Energy Office. Air conditioners don’t just cool air; they dehumidify it. Otherwise, your home would be cool and clammy. Size does matter, but it isn’t just a matter of getting a big machine. A properly sized AC unit is one that is chosen to fit your home. This includes factors such as insulation, windows, air leakage, roof characteristics and which way the windows face. Air conditioners that fit the homes they serve may run a bit longer, but they also keep the occupants more comfortable and use less electricity than oversized units.

Myth: The air conditioner won’t run as much if you keep ceiling fans turned on.
Reality: Totally false. Fans don’t cool air; they just move it around. Use the ceiling fans when you’re in the room, but turn them off to save electricity when you leave.

The big truth is that best way to save money on cooling your home is to use the air conditioner sensibly. Keep the thermostat at a reasonable setting and make sure your doors and windows are free of drafts. Windows are great solar collectors; use window coverings to keep the sun from heating up your room. Use a programmable thermostat or simply raise the temperature a few degrees when you leave.

Summer electric bills are always a balancing act. Don’t let air conditioning myths tip you in the wrong direction—and don’t let the repair or replacement of your system’s component parts melt your budget, either. Learn how American Home Shield home warranty can help keep your unit and budget in check.