Premium efficiency up to 19 SEER2 and 10 HSPF2. This unit can be configured to communicate with R454B YDC condensing units. It features an all-aluminum evaporator coil for superior corrosion resistance and a constant-torque ECM blower designed for efficient 4-stage operation. Electric heat accessory kits are available in 5, 8, 10, 15 and 20 kW for supplemental or emergency heating. Easy to install, it is compatible with most standard 24 VAC heat pump thermostats and uses factory-installed TXV metering. For serviceability, the cabinet is fully insulated with dual front panels, a slide-out blower and coil, and polymer condensate pans with a UVC inhibitor; multiple drain options and a low-leakage, factory-sealed cabinet further simplify maintenance. Multi-position installation supports upflow or horizontal right standard with field-convertible left or downflow.