They can last 15-20 years depending on unit quality, daily use, installation quality, and maintenance.
An improperly installed system may start breaking down within 3 years. We’ve seen this happen when moisture was not properly purged from the system during installation. And a lower-quality system may only last 8-10 years. But with proper installation and maintenance, it may last longer. When properly installed and maintained, a high-efficiency system can last 15-20 years and has warranties that match!