As of February 2015, Trane's air conditioner model lines are the XB series, the XR, the XL and the XV. Each model is backed by Trane's warranty, and all except the XB300 qualify for the Energy Star program. Trane only produces central air conditioners.
The XB series includes the XB300, XB13, XB14 and XB16. Prices range from inexpensive to moderate, with the XB300 being the least expensive model Trane offers. The nominal sound levels range from 78 to 82, and the maximum Seasonal Energy Efficiency Ratings range from 13 to 16.50.
The XR series includes the XR13, XR15, XR16 and XR17. Prices tend to be moderate. The nominal sound levels range from 74 to 75, and the maximum SEERs range from 14.50 to 18.
The XL series includes the XL15i, XL16i, XL18i and XL20i. Prices range from moderate to expensive. The nominal sound levels range from 72 to 73, and the maximum SEERs range from 16.50 to 20.
The XV series includes the XV18 and the XV20i Variable Speed. Both are expensive, with the XV20i being the most expensive model Trane offers. The XV series is considerably quieter than the other models -- both of the XV models have a nominal sound level of 55. The XV18 has a SEER up to 18, while the XV20i has a SEER up to 21.