How long does an AC unit last in Phoenix?

How long do AC units last? It depends on how many hours they run, and in Phoenix that’s a lot of hours. Manufacturers quote averages based on typical use across the country, so it helps to know what those numbers assume before comparing them to a system that cools a desert home from spring into fall.

How long AC units last on average

Manufacturer estimates for a central air conditioner vary. Trane says a central air conditioner “will last about 15 years.” Carrier and Lennox both put the average at 15 to 20 years for a well-maintained system. Carrier adds that some units last up to 25 years with diligent care, while neglected systems might fail around the 10-year mark.

Not every source is that optimistic. The home inspectors’ association InterNACHI lists central air conditioners at 7 to 15 years. The range is wide because life expectancy depends on use, climate, installation, and upkeep, not just the equipment.

The type of system matters as well. Lennox puts ductless mini-splits at 15 to 20 years, similar to central air, and says window units have a much shorter lifespan of five to eight years. If your home has a heat pump rather than a cooling-only AC, the same equipment also heats the house in winter, though Phoenix’s heating season is short and light.

Why Phoenix is hard on an air conditioner

Run time is what wears out an air conditioner, and Phoenix’s cooling season is long. The National Weather Service’s 1991–2020 averages put Phoenix’s first 100-degree day on May 2 and the last on October 5, with the first 110-degree day on June 11.

Manufacturers call this out directly. Trane says that “if you live in Florida or the desert southwest and run your AC long and hard year after year, it may wear out before the average life expectancy.” Carrier makes the same point: a unit in a region with short, mild summers “will naturally accumulate fewer running hours” than one facing long summers in the South. Lennox says hot temperatures can put more stress on the system and shorten its lifespan.

Your thermostat setting matters too. Trane notes that keeping the house “at a frosty 68 degrees in the summer” can wear a system out earlier. InterNACHI adds a caveat to its own chart: its estimates assume normal wear and tear, “not extreme weather.”

What helps an AC unit last longer

Maintenance is the part you control. The Department of Energy says neglecting it “ensures a steady decline in air conditioning performance while energy use steadily increases.” Carrier says that without maintenance, an AC unit’s lifespan may drop to 10 to 12 years.

The habits that matter most:

• Filters: The Department of Energy recommends cleaning or replacing filters every month or two during the cooling season. A clean filter alone can cut energy use by 5% to 15%.
• Coils: Have a technician check the evaporator coil every year and clean it as needed, per the Department of Energy. Check the outdoor unit after dust storms, too.
• Clearance: Keep plants and debris at least 2 feet back from the outdoor unit so it gets enough airflow.
• Professional service: Trane recommends a professional tune-up in early spring. Follow a month-by-month maintenance schedule to time it before summer.

Signs it’s time to replace your AC unit

ENERGY STAR suggests considering replacement when a heat pump or air conditioner is more than 10 years old. Age alone isn’t the deciding factor, but it tells you when to start paying attention. Trane lists the main indicators together: “old age, increasing number and cost of AC repairs, decreased comfort, and higher cooling bills.”

Other signs from ENERGY STAR, Trane, Carrier, and Lennox:

• Repairs are getting more frequent and more expensive
• Cooling bills are rising
• Some rooms are too hot or too cold
• The unit is getting louder

Carrier says that if a repair approaches 50% of the value of a new system, it’s usually time to upgrade. Before approving a major repair on an older unit, compare the quote against what a new AC costs in Phoenix.