HVAC systems are basic systems for your home that experience heavy use. If you live in a climate where all four seasons are extreme, you can run your HVAC almost year-round. Residents of more temperate climates may cause less wear and tear on their systems. Although they are very powerful, air conditioning systems are designed to withstand this use and last, on average, between 15 and 25 years.
These systems tend to be expensive to purchase and install, so much so that they are expected to last for decades, but 15 to 25 years is a wide range, and there are several steps you can take to extend their lifespan. Replacing furnaces urgently in the intense cold of winter is more expensive than when the installation is completed quietly out of season (plus, you'll have to pay to stay elsewhere until the replacement is complete, which can take longer if technicians are required). While this can make you feel like you're constantly repairing or replacing major components, it also helps spread the cost of replacements so you don't have to replace everything at the same time. And you're right, replacing heating, ventilation and air conditioning systems can be expensive, so it's a good idea to plan and save before air conditioning units or furnaces need to be replaced immediately.
And when a major problem occurs, the decision to repair or replace the air conditioner can add years of comfort by replacing an important component. As a result, service and minor repairs are performed more frequently and extend the overall lifespan of HVAC systems. In addition, they cover replacement costs when it's time to replace them.