Q: How long will my brand new A.C. system Last? There is no definitive, one-size-fits-all answer to this query. Assuming the apparatus has no manufacturing defects, isn’t operated heedlessly, and it undergoes an annual inspection (just like most cars), you can expect about 15 to 18 years of service. Obviously, if the unit isn’t maintained and/or repaired properly it probably won’t run that long. “If you take care of your tools they will take care of you.” Modern-day systems a