How Long Does an AC Last?
A central air conditioner lasts 15 to 20 years — 12 to 17 in a hot, heavy-use climate. The signs it's near the end, and when age alone says replace.
15–20 years
Typical range
~17 years
Planning average
Don’t know how old your central air conditioner is?
Use the serial number to estimate its manufacture date and age.
Check central air conditioner age →Where you live decides where in that range you land far more than the brand does: a system in a mild climate can run past 20, while one that cools a house in Phoenix or Houston for eight months a year is often done by 12 to 15.
ENERGY STAR treats the 10-year mark as the point to start planning — not because the AC will fail at 11, but because 10 years is roughly the midpoint of its life and the efficiency gap to a new unit is already wide.
How long does a central air conditioner last?
15 to 20 years for central AC, less for units that work harder:
| System | Typical lifespan | Notes |
|---|---|---|
| Central air conditioner | 15–20 years (12–17 with heavy use) | The compressor is the part that ends its life |
| Heat pump | ~10–15 years | Runs year-round, so more hours on the compressor |
| Ductless mini-split | ~15–20 years | Similar to central AC; each head is replaceable |
| Window unit | Shorter | Almost always cheaper to replace than repair once out of warranty |
Sources: NerdWallet, Bob Vila, ENERGY STAR.
What shortens an AC's life?
- Hot climate + long cooling season
- An AC in the desert Southwest simply runs three to four times the hours of one in New England (Bob Vila)
- Skipped maintenance
- A yearly service catches low refrigerant, a weak capacitor, or a dirty coil before they overwork the compressor
- Dirty filter or coil
- Restricted airflow makes the system run hotter and longer for the same cooling — change the filter every 1–3 months
- Oversized unit
- Short-cycles — starts and stops repeatedly — which is the hardest duty on the compressor and its start components
- Running low on refrigerant for years
- A slow leak left unfixed lets the compressor run hot and starved, and that is what kills it early
- Coastal salt air
- Corrodes the outdoor condenser coil; homes near the ocean often replace sooner
What happens to an AC as it ages?
Early life (roughly the first decade): most repairs are cheap, isolated parts — a capacitor ($80–$400), a contactor, a fan motor. A failure here isn't a sign the system as a whole is failing.
Mid-life (around the ENERGY STAR 10-year checkpoint): wear-related components become a more regular repair-vs-replace consideration — a leaking coil, or the compressor. Watch the electric bill and how evenly the house cools; both tend to drift before anything actually breaks.
Late life (approaching or past 15–20 years): a major failure carries more weight, because the repair cost has to be weighed against how much useful life is realistically left. Replacing on your own schedule, in spring, beats waiting for a July breakdown at emergency rates with no time to compare quotes.
Past typical service life, on an R-22 system — most units installed before about 2010 — a refrigerant leak is close to a hard stop: the EPA banned R-22 production in 2020, so a recharge now costs far more than it is worth.
When should you replace an AC instead of repairing it?
Any one of these points to replacement:
- The repair quote is half the price of a new unit or more (NerdWallet).
- Age × repair cost is over $5,000 — a $500 repair on an 8-year-old unit is $4,000, worth doing; the same repair at 12 years is $6,000, and points to replacement.
- The compressor has failed and the unit is past about 10 years.
- It runs on R-22 and has developed a leak.
- Bills are climbing and the house cools unevenly despite a recent service.
Shop air conditioners: window units, central air and mini-splits
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Shop now →How do I find out how old my AC is?
The rating plate on the outdoor unit — a metal label on the side of the condenser, near the refrigerant line connections. Many list a plain "Mfg Date"; if not, the date is in the serial number, and the format is brand-specific. Decode it with our HVAC age tool — it reads Goodman, Carrier, Lennox, Trane, York and more — or read the printed date directly.
How to make an AC last longer
- Book a yearly service before cooling season — it is the single biggest lever on compressor life.
- Change the filter every 1–3 months. A clogged filter is the most common reason an AC runs hot. The right size and MERV rating matters too.
- Keep the outdoor unit clear — two feet of space, no grass clippings or cottonwood packed into the coil, and hose it down gently once a year.
- Fix a refrigerant leak promptly instead of topping it up each summer — running low is what wears the compressor out early.
- Don't set the thermostat lower than you need. Every degree is more runtime, and runtime is what the lifespan is measured in.
If you are weighing a replacement against a repair, central AC vs a window unit covers whether whole-house cooling still makes sense for your layout.
Shop air conditioners: window units, central air and mini-splits
A family company with a strong Trustpilot rating and free shipping on every order.
- America's Trusted Mini Split Brand — installed in over 500,000 homes
- As featured in Popular Mechanics, Entrepreneur, Business Insider and the Chicago Tribune
- ENERGY STAR certified — a range of efficient, energy-saving heating and cooling products
We may earn a commission if you use this link. How this works
Shop now →Frequently Asked Questions
How long does a central air conditioner last?
15 to 20 years on average (NerdWallet), and 12 to 17 years for a well-maintained unit under normal demand (Bob Vila). In a hot climate where the AC runs most of the year, expect the lower end.
Is it worth replacing a 15-year-old AC?
Often, yes. ENERGY STAR treats 10 years as the point to start planning, so a 15-year-old unit is near the end of its life, likely running 30 to 50% less efficiently than a new one, and one compressor failure away from a forced replacement. If it still cools well and has had no major repairs, you can run it — but do not sink a big repair into it.
How long does a heat pump last?
Roughly 10 to 15 years — a few years less than a cooling-only AC, because a heat pump also runs through the winter, so it logs far more hours. ENERGY STAR uses the same 10-year checkpoint for heat pumps and air conditioners.
What's the 50% rule for AC replacement?
If a repair quote comes to half the price of a new unit or more, replace instead of repairing (NerdWallet). A related rule of thumb: multiply the AC's age by the repair cost, and if it clears $5,000, replace.
Does an air conditioner get less efficient as it ages?
Yes. Wear on the compressor and fan motors, a slowly fouling coil, and any small refrigerant loss all drag the effective efficiency down over time. A 15-plus-year-old unit can use 30 to 50% more electricity for the same cooling than a current model (NerdWallet).
Sources
- NerdWallet — Air Conditioner Replacement Cost — many air conditioners have a lifespan of 15–20 years; if a repair equals half the price of a new unit, replace; newer units run 30–50% more efficiently; new central AC $2,500–$4,500
- Bob Vila — How Long Does an Air Conditioner Last? — a well-made, well-maintained central AC under average demand lasts 12–17 years; lasts decades in a temperate region, far less in the desert Southwest; warning signs — grinding/rattling noises, humidity, excess dust
- ENERGY STAR — When Is It Time to Replace? — consider replacing when your AC or heat pump is more than 10 years old — roughly the midpoint of its life; an ENERGY STAR unit can save up to 20% on heating and cooling costs and uses 8% less energy than a conventional new model; also replace if repairs are frequent and bills are rising
- U.S. EPA — Phaseout of Class II Ozone-Depleting Substances (R-22) — the EPA banned production and import of R-22 on January 1, 2020; existing systems can still be serviced, but only with reclaimed or previously produced R-22, and price and availability may change
The Air Conditioning Series
- 1How Old Is My Furnace or AC?Decode the serial number and see where it sits against a typical lifespan.
- 2How Long Does an AC Last?You’re here — this article.
- 3How Much Does an AC Capacitor Replacement Cost?The cheapest and most common AC repair — $80 to $400, and why a $15 part costs that much.
- 4How Much Does an AC Compressor Cost to Replace?Cost by system size, warranty vs not, and when replacing the whole system is the better call.