Today’s central air conditioning systems are much more efficient than their predecessors. The industry uses a rating called SEER for central systems, which is an acronym for Seasonal Energy Efficiency Ratio. Essentially, a higher SEER rating means the air conditioner uses energy more efficiently. When other factors such as thermostat settings are kept equal, a higher SEER results in lower monthly utility bills for the owner or occupant. A central air conditioning unit rated at 13 SEER uses almost a third less electricity than a 10 SEER system.
Some outside A/C units are rated at a range, such as 14/15 SEER, depending on what type of indoor equipment they are paired with. For example, if paired with a manufacturer recommended evaporator coil and a variable speed furnace or variable speed air handler, an outside unit could be rated as a 15 SEER system. Otherwise, the rating would be 14 SEER.
As you might imagine, higher efficiency A/C equipment costs more to build. Why? For one reason, more efficient condensers and evaporators contain more metal in their extra coils. Additionally, to gain higher efficiency, the systems may have more complex technology such as motor speeds and electronics.
TO READ MORE GO TO: http://www.airconditioning-and-heating.com/how-acs-work/