Summer typically isn't the best time to buy an air conditioner. Some air conditioners last anywhere from 15 to 20 years, while others might only be around for 8 to 10. Portable air conditionersTrevor RaabPortable air conditioners are a relatively affordable way to target airflow problems around your home or apartment. For window air conditioners, you should check the seal between the air conditioner and the window frame at the start of spring and summer. With a set schedule, the air conditioner automatically raises and lower temperatures throughout the day, cutting down on its overall runtime and effort.