Can an AC last 40 years?

Can an AC last 40 years is extremely rare and not expected, as average lifespan of central AC is 15 to 20 years and maximum with excellent care is 25 to 30 years, so 40 years is possible only for very old heavy-duty units that have been heavily repaired. Old AC units from 1970s and 1980s like Trane and Carrier built with very heavy copper coils and simple compressors could last 30 to 40 years if compressor replaced multiple times and coils cleaned regularly, but they operate at 6 to 8 SEER efficiency, costing 2 to 3 times more in electricity than modern 16 SEER unit. Modern AC units from 2000s onward use thinner aluminum coils and more electronics that typically fail after 15 to 20 years, with compressors lasting 12 to 15 years, and control boards failing after 10 years. Factors that could allow AC to reach 40 years include running only 2 to 3 months per year in mild climate, meticulous maintenance with coil cleaning twice yearly, indoor storage in winter, and replacing major parts like compressor twice at 1,500 to 2,500 dollars each, capacitor every 5 years at 150 to 300 dollars, and contactor every 7 years. However, after 20 years, refrigerant like R-22 is phased out and parts become unavailable, and efficiency loss makes replacement more economical, as new 20 SEER variable speed can save 500 dollars per year. So while technically possible with old heavy unit, it is not practical or economical for modern AC to last 40 years.