Regular maintenance with a reputable HVAC company is a simple yet extremely important thing you should do to make sure your mini split unit performs efficiently and lasts you a long time. This includes cleaning or replacing air filters, checking and cleaning the indoor and outdoor coils, a vacuum of the drain lines, and inspecting the refrigerant levels. I have had many customers who saved a small amount by skipping regular maintenance, only to pay a hefty price when their system breaks down and requires replacing many years ahead of schedule.