This model outputs ON/OFF signal to control fan
operation. When the system is in mode like unoccupiedOff,
safety, it outputs false so that fan should be
OFF and provide 0 pressure rise; When the system is in
mode like unoccupiedNightSetBack,occupied,unoccupiedWarmUp,
unoccupiedPreCool, it outputs true so that fan
should be ON and provide preRis pressure
rise.