The System Selection preferences set the default values of the selection trees of the System Selection Wizard as specified by the user. For example, if your site requires a discharge air sensor on all VAV boxes, select Discharge Air Temperature on the VAV Single Duct Tree.
Setting preferences before going through the System Selection process for similar systems allows you to save time during selection and helps keep your systems consistent. Set preferences on the selection trees to match your local climate conditions. These preferences only specify the starting values for the System Selection options. System Selection preferences do not prevent you from making particular selections on any given system.