Johnson Controls’ Premium Efficiency vertical-stacked water-source heat pumps offer efficiency — as high as 16.6 EER and up to 18.5 EER in geothermal applications — and a flexible design that allows for simple zoning, tenant metering and building expandability. The heat pump interfaces with standard thermostats and includes microprocessor-based controls. The model also features outside air opening with collar and motorized damper, up to three supply air openings, sound-attenuating discharge baffles, ECM motors and MERV 8 filters.