Installed 2.5 ton Carrier R-454B heat pump system with electric heat kit. Installed Ecobee pro thermostat. Installed new secondary drain pan. Built and installed new supply plenum and return plenum with 20x25 Aprilaire media filter. Rebuilt primary drain, added SS2 / SS3 safety switches. Pressure tested system with nitrogen and pulled vacuum. Sealed all ductwork connections with mastic / hardcast. Cleared primary drain with CO2 and primed trap with water. Weighed in R-454B refrigerant, 62 ambient temp. Tested heating and cooling operation. Everything is working at completion of install.