Whether you have a brand new AC installation or you're dealing with an older unit, there are a few things you can do to ensure your system continues to operate at peak performance throughout the year. First, follow the manufacturer's guidelines for routine maintenance and tune-ups. Manufacturers usually recommend that your HVAC unit be inspected and maintained at least once per year. Next, clean or replace your filters every 30 days, particular during periods of heavy system use. Weatherproof your home to ensure the cool air stays indoors during the summer and the warm air remains inside during the winter. You can do this by applying caulk or weatherstripping around all doors and windows. Finally, keep all windows and doors closed, and close the curtains and shades on windows facing the sun during the winter. Closing the drapes and shades in the winter helps to keep your home warmer.