nstalled Payne 4 ton R-454B condenser, mounted on brackets to wall. Installed mobile home straight electric air handler with heat strips and R-454B evaporator coil. Installed new disconnect box and wiring for the outdoor unit. Built and installed new supply plenum to connect to the flex duct. Sealed connections with mastic / hardcast. Installed Ecobee Lite thermostat. Pressure tested system with nitrogen and pulled vacuum. Charged AC with R-454B refrigerant. Tested heating and cooling operation. Everything is working at completion of install.