As the mercury rises, many Iowans might be kicking on their air conditioners. A local heating and cooling company says its important to keep A/C units in proper working order. Denise Wiles, with J and S Heating and Air Conditioning says you need to keep the unit's air filter clean. She says many people don't even realize there is an air filter. Wiles says the filter will needed to be changed periodically, depending on where you live. She says it will be more often if you live near gravel or dirt roads. Wiles also says air conditioners should be inspected and given a "tune up" at least once a year.