Central air conditioning units can be highly energy efficient, with many of them certified as energy efficient by the Department of Energy's Energy Star program. These air conditioners are estimated to be up to 15 percent more efficient than non-certified models.
Installing high-efficiency central air conditioning units with Energy Star ratings can potentially save a great deal of money for households due to their higher efficiency. Cost savings for households with air conditioning units 12 years old or older are estimated to be as high as 30 percent. Central air conditioners are also more efficient than most window-mounted air conditioners, though issues with ventilation systems can sometimes reduce these advantages.