This is a really common question, along with “When will I know when it’s time to replace it?”
The average life expectancy of a furnace is 20 years, and is 11-14 years for an A/C system. But these statistics were from a national study. This will obviously be a climate based scenario.
There are numerous issues involved, like how often it gets serviced, what the thermostat setting preference is, how often the air filter gets changed, what kind of filters are used, rental property, etc. We actually do have a handful of customers with A/C equipment older than I (1976), but those are rare circumstances. We have been servicing and maintaining them for decades!
Freak things can happen that are sometimes beyond your control, especially with air conditioners. Power surges during a storm can totally destroy them in a heartbeat. And one minor problem can cause a more serious one that seals the fate of the system.
So it’s not unlike us as humans. You can’t ignore “the odds”. They must be factored into any estimates you make.
But the most important factor by far is the present condition of the equipment.
So we often get asked the question “Will it get me through this year?”.
Let’s think about that. Obviously each year the system is around, it statistically has less years of its lifespan left. Let’s say that the system has already met and surpassed the “average life expectancy”. This is not totally unlike an elderly patient asking the doctor if they’ll be seeing them again for the next annual checkup if you go by statistics alone and don’t factor in the present condition of the patient.
The only honest answer a good technician can give is that it’s impossible to predict with any degree of accuracy.
But I can say with little reservation that the systems being made today won’t last as long as the old ones did. The constant push for higher efficiency comes with a price. And system longevity just isn’t factored in. It doesn’t fit in that equation, nor does the push to keep the equipment prices down either. Older equipment – furnaces and A/C units are much more tolerant to adverse conditions than the newer counterparts. That’s why so many really old ones are still out there. The newer equipment must be properly installed and maintained or they will achieve much less reliability, longevity and energy efficiency.
Regular maintenance performed by a conscientious, experiencedtechnician can make your old system operate more efficiency, reliably and last a lot longer than you can imagine.