A separating module for a ventilation device has a housing that surrounds a separating element designed to separate liquid particles from a gas flow. A line module and a ventilation device with such a separating module and such a line module are provided. The housing of the separating module is designed to be connected to the line module that has at least three geometrically parallel channels and the housing of the separating module has corresponding housing openings to be connected to the at least three channels. Several separating modules and several line modules can be combined to adapt the ventilation system as needed.