Central AC System GuideRoutine maintenance protects both efficiency and the equipment itself. ENERGY STAR recommends inspecting the filter every month and having a professional check the cooling system in spring. The Department of Energy reports that routinely replacing the filter alone can lower an air conditioner's energy consumption by 5 to 15 percent.
Filters first
The filter is the single most important homeowner task. ENERGY STAR advises inspecting, cleaning, or changing the air filter once a month, because a dirty filter makes the heating and cooling system work harder to move air through the home.
The payoff is measurable. The Department of Energy reports that routinely replacing the air filter can lower an air conditioner's energy consumption by 5 to 15 percent. A clean filter also keeps dust off the evaporator coil, which is where neglect turns into bigger problems.
Coils and the condensate drain
Dirty coils quietly rob the system of capacity. ENERGY STAR advises cleaning the evaporator and condenser coils, noting that dirty coils reduce cooling ability and increase energy costs as the system runs longer to reach the set temperature.
The condensate drain deserves the same attention. ENERGY STAR recommends checking and inspecting the condensate drain, because a plugged drain can cause water damage and raise indoor humidity. Keeping the drain clear protects both the equipment and the surrounding space.
Refrigerant charge and airflow
Refrigerant level is a professional check, not a homeowner one. ENERGY STAR advises checking the air conditioner's refrigerant level and adjusting if necessary, noting that improper levels reduce efficiency and shorten equipment life.
Airflow ties the whole system together. ENERGY STAR reports that airflow problems can reduce a system's efficiency by up to 15 percent, so clean blower components and unobstructed ducts matter as much as a full charge. A trained technician can verify charge and airflow together during a tune-up.
Schedule a professional tune-up
Some maintenance belongs to a contractor. ENERGY STAR recommends checking the cooling system in the spring and the heating system in the fall, timing the pre-season visit so problems surface before peak demand.
A professional visit also catches efficiency drains a homeowner cannot see. ENERGY STAR estimates that about 20 to 30 percent of the air moving through a typical duct system is lost to leaks, holes, and poorly connected ducts, and a contractor can seal ducts, verify charge, and clean components in one visit.