Regular maintenance is vital to maximizing the life of your AC unit. This should include cleaning or replacing your filters each spring, as well as scheduling ongoing maintenance by a licensed HVAC technician. Also, here are some day to day tips that will extend the life of your AC unit and reduce your electricity bill: close your curtains and blinds during the day to limit sunlight. keep windows and doors closed so that the hot air does not come in. when it’s extremely hot outside, raise the temperature of your thermostat a few degrees (you won’t even notice).