When selecting a system, you first choose the overall type of system and a specific configuration to create. For example, you may select VAV as the system type and Single Duct as the specific configuration to use. See the Selecting a System (Creating a New System) steps and the Applications section for details on the System Selection options:
Air Handling Units
Fan Coil -- Fan Coil Applications
Unit Ventilators -- Unit Ventilator Applications
Heat Pumps -- Heat Pump Applications
VAV
Central Heating -- Central Heating Applications
Central Cooling Plants
Simple Central Plant -- Simple Central Plant Applications
Custom Applications -- Custom and Monitoring Supervisory Control Only Applications
Monitoring Supervisory Control Only -- Custom and Monitoring Supervisory Control Only Applications