Can an AC unit last 30 years?

Can an AC unit last 30 years, theoretically yes but very rare for central ducted AC, with most lasting 15 to 20 years, but some well-maintained units from 1980s and 1990s have lasted 25 to 30 years due to heavy-duty construction and simple components, though efficiency was only 8 to 10 SEER versus modern minimum 14.3 SEER2 in 2025, so operating cost much higher. For central AC like old Trane and Carrier units from 1990s with thick gauge steel and simple reciprocating compressors, some have lasted 25 to 30 years with only minor repairs like capacitor at 150 to 300 dollars and contactor at 150 to 250 dollars, but by 20 years efficiency drops 20 to 30 percent due to coil corrosion and wear, causing electric bills 30 to 50 percent higher than new 16 SEER unit that would save 300 to 600 dollars per year. Modern AC units including Goodman GSX14, Trane XR14, and Carrier Comfort 14 are designed for 15 to 20 year life with lighter cabinets and more electronics like control boards that fail after 10 to 12 years at 300 to 600 dollars, so 30 year lifespan unlikely for modern units, though possible with meticulous maintenance including annual tune-up at 100 to 150 dollars, filter changes every 2 months, coil cleaning twice yearly, and replacing capacitor proactively every 5 years. Ductless mini-split Mitsubishi Hyper Heating can last 20 to 25 years due to inverter technology. So AC can last 30 years in rare cases but not expected, average is 15 to 20 years, and replacement after 15 years often more economical due to efficiency gains.