Point contact valve seats for film applications

In a ventilation system (10,10a) of a motor vehicle, a film valve (44a,46a,48a) can selectively open and close an air path opening defined by a housing with a rib (56g) or projection that encircles such opening. The rib can define a point contact between the film valve and the housing when viewed in cross-section. The rib geometry can include substantially straight edges in cross-section and/or can include arcuate edges. Different geometry can define the rib at different cross-sections. The point contact defined between the rib and the film valve substantially reduces noise generated when the film valve moves relative to the rib, especially when the film valve has been subjected to a harsh environment.