Air filter system, air filter element and method for exchanging an air filter element

The system (1) has an air filter element (30) with filter media, a radially acting annular seal (33) placed at an axial end of filter element, a housing (10) with an upper portion (11), a clean air connection (16) for discharging clean air from housing. The housing has an annular accommodating area axially opened towards interior space of housing surrounding clean air connection and engages radially acting annular seal of filter element. The annular seal has surface arranged opposite to sealing surface with annularly surrounding indentations (339) in radial direction.