"EER (Energy Efficiency Ratio) is a measure of how efficiently a cooling system will operate when the outdoor temperature is at a specific level (95°F). The higher the EER, the more efficient the system.
SEER (Seasonal Energy Efficiency Ratio) is most commonly used to measure the efficiency of a central air conditioner. The higher the SEER, the more efficient the system. SEER measure how efficiently a cooling system will operate over an entire season.
All LG units are rated in EER. Split Units are rated in EER and SEER. These ratings can be found on specification sheets for the model, or on the Energy Star website (www.energystar.gov