Installed two complete HVAC systems including air handlers and condensers. Each system was properly sized for its zone using load calculation data. I mounted and leveled the outdoor condenser units, brazed in the refrigerant lines, and pressure-tested them with nitrogen up to 350 psi. After pulling a vacuum to below 500 microns, I charged both systems with factory-specified R-410A. I also wired and programmed new smart thermostats, checked airflow at each supply register, and verified proper operation through full system startup and performance testing.