Johnson Controls. Two Echelon AC8B split-system air conditioners and one Echelon HC8B heat pump have been designated Energy Star Most Efficient 2012, which recognizes the most efficient products among those that qualify for Energy Star certification. The products feature performance levels of 18.0 SEER, 12.5 EER, and 9.6 HSPF and provide diagnostic and setup information in plain text as well as access to outside temperature data.