The worst thing young adults can do is go to graduate school because they aren't sure what else to do or they can't find jobs. Grad school, after all, is often an extremely long commitment. A Ph.D., for example, can take six years.
The average lifespan for an air conditioner is 10 to 15 years. Some air conditioners last up to 20 years. As interesting as these data points may be, they don't tell you the whole story. The issue is that a variety of factors affect the lifespan of an air conditioner.
Typical costs: Adding central air conditioning to an existing forced-air heating system in a 2,000-square-foot house averages $3,500-$4,000, and can be done by two technicians in 2-3 days, with little or no change to the existing ducting; if ducts must be added, the work time doubles, as does the cost to $7,000-$8,000 or more, according to ThisOldHouse.com .