Central AC systems cool air at a central location and distribute it to and from other rooms by one or more fans and ductwork. The work of the AC compressor makes the whole cooling process possible.

SEER Rating: Seasonal Energy Efficiency Ratio, or the ratio of the cooling output of an AC system during a typical cooling season, divided by the energy it uses in Watt-Hours. Like miles-per-gallon in your car, the the higher the SEER Rating the more cooling comfort you get per dollar spent on energy.