I have a two zone model in which I have defined a dummy exhaust fan to balance air system flows when using ZoneMixing. However in the output the Zone Exhaust Air Mass Flow Rate in the zone with the dummy fan is always 0, while this should be the fixed flow rate of the fan. (correct me if I'm wrong) The fan is Decoupled. The exhaust fraction is set to be unbalanced. In the ZoneAirMassFlow object Adjust Zone Mixing For Zone Air Mass Flow Balance is on ('yes'). According to the output the availability schedule of the fan is ok. Does anyone know what could be the cause of this issue?