How would you design a VRF system for a multi-story commercial building?

VRF (Variable Refrigerant Flow) system design starts with accurate zone-by-zone cooling/heating load calculations considering occupancy, equipment, orientation, and schedules. Select outdoor unit capacity at 100-130% of total connected indoor capacity accounting for diversity factor. Design refrigerant piping within manufacturer limits for length, height difference, and branch sizes. Position indoor units for uniform air distribution, and plan condensate drainage. Include branch selector boxes for heat recovery systems. Consider defrost cycles, fresh air handling, backup heating for extreme conditions, and BMS integration. Verify refrigerant charge calculations and plan for commissioning.