The Trane XL16c is a more efficient and powerful heat pump than the XL14c. All versions of the XL16c have superior Seasonal Effective Efficiency Ratings and Heating Seasonal Performance Ratings than any XL14c model, as of 2015.
The Trane XL16c outperforms the XL14c in terms of raw heating and cooling power, achieving a maximum SEER of 16.4 and HSPF of 9 versus the XL14c's 14.25 SEER and 8 HSPF ratings. In most other respects these heat pumps are very similar, with both employing Trane's Climatuff two-stage compressor system, Spine Fin aluminum radiator design and R-410A refrigerant. Both also feature variable-speed fan motors to reduce overall noise output and improve efficiency.