What does SEER mean? SEER means Seasonal Energy Efficiency Ratio. The higher this number, the greater the cooling efficiency…and the greater your energy savings. Gov. regulations require all new models to meet 13 SEER - We offer air conditioning up to 19.5 SEER Today’s high efficiency air conditioning systems provide better cooling and dehumidification. Trane’s XL19i high-efficiency air conditioner has a SEER rating up to 19.00, which means a lower monthly operating cost. Trane offers the best warranties in the industry at 10 years.