A heater element with a functional material-containing layer includes: a honeycomb structure including an outer peripheral wall and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from a first end face to a second end face to form a flow path, at least the partition walls being made of a material having a PTC property; a pair of electrodes provided on the first end face and the second end face of the honeycomb structure; and a functional material-containing layer provided on a surface of the partition walls.

A heater element including a honeycomb structure and a functional material-containing layer, wherein the honeycomb structure has an outer peripheral wall and partition walls provided inside the outer peripheral wall, the partition walls partitioning a plurality of cells that form flow paths extending from an inlet end surface to an outlet end surface, and at least the partition walls are made of a material having PTC characteristics, and wherein the functional material-containing layer is provided on a surface of the partition walls, and a thickness of the functional material-containing layer increases from the inlet end surface toward the outlet end surface.

A heater element including a honeycomb structure and a functional material-containing layer, wherein the honeycomb structure has an outer peripheral wall and partition walls provided inside the outer peripheral wall, the partition walls partitioning a plurality of cells that form flow paths extending from an inlet end surface to an outlet end surface, and at least the partition walls are made of a material having PTC characteristics, and wherein the functional material-containing layer is provided on a surface of the partition walls, and a thickness of the functional material-containing layer increases from the inlet end surface toward the outlet end surface.

An air purification system includes an air purifier with a control unit and a filtration unit, at least one human-machine interface, at least one nomadic air sensor designed to be able to be coupled to the air purifier, or uncoupled from the air purifier, the control unit being designed to control the filtration unit according to at least one coupled operating mode taking into account measurement feedback from the air sensor, and one uncoupled operating mode not taking into account measurement feedback from the air sensor, wherein in the uncoupled operating mode of the air purifier, the human-machine interface is designed to display measurements from the nomadic air sensor.

An air purification system includes an air purifier with a control unit and a filtration unit, at least one human-machine interface, at least one nomadic air sensor designed to be able to be coupled to the air purifier, or uncoupled from the air purifier, the control unit being designed to control the filtration unit according to at least one coupled operating mode taking into account measurement feedback from the air sensor, and one uncoupled operating mode not taking into account measurement feedback from the air sensor, wherein in the uncoupled operating mode of the air purifier, the human-machine interface is designed to display measurements from the nomadic air sensor.

An air-treatment system for a confined environment, in particular the cabin of a vehicle, includes: a supply unit including an inlet port, a delivery port, and a purge port, the supply unit being configured for delivering air to said confined environment through the delivery port; and a first filtering device having a first filtration level, and a second filtering device having a second filtration level, each of the first and second filtering devices being arranged in fluid communication with the inlet port of said supply unit at a circuit node. A single flow-control valve determines inlet flow through one or other of the filtering devices.

A road vehicle with a vehicle frame and a rear axle connected to the vehicle frame is provided with an ambient air purification device with filter elements for removing dust, particulate matter, and gases from ambient air. The ambient air purification device is arranged transverse to a longitudinal vehicle axis in an exterior region of the road vehicle at a vehicle rear of the road vehicle in an underfloor region such that at least the filter elements are arranged behind the rear axle of the road vehicle in a travel direction of the road vehicle. The ambient air purification device is received in an installation space of the vehicle frame. The ambient air purification device is flowed through in longitudinal vehicle direction. A free outflow zone of the ambient air purification device is arranged, in travel direction of the road vehicle, behind the ambient air purification device.

An air filter for a ventilation system of a motor vehicle may include a plate-shaped filter body of a folded filter material and at least one sealing strip secured to a lateral edge of the filter body. Adjacent folds of the filter body may be connected to one another via a seam, may follow one another in a longitudinal filter direction, and may extend in a transverse filter direction. The at least one sealing strip may have at least one removal opening penetrating the at least one sealing strip. At least one removal nozzle for removing air flowing through the air filter may be securable to the at least one removal opening.

A vehicle air control system includes a vehicle body that defines an interior. A first particulate matter sensor is coupled to an exterior of the vehicle body. A second particulate matter sensor is disposed within the interior of the vehicle body. A temperature sensor is coupled to the exterior of the vehicle body. A vehicle speed sensor is coupled to the vehicle body. A heat, ventilation, and air condition (HVAC) system is disposed within the interior of the vehicle body. The HVAC system includes an inlet door rotatable between a first position, a second position, and a third position therebetween. A controller is configured to receive a signal from at least one of the first and second particulate matter sensors, the temperature sensors, and the vehicle speed sensor. The controller is configured to rotate the inlet door in response to the signal.

A filter element includes: a filter frame; a bellows of a filter medium accommodated in the filter frame; and a seal externally circumferential on the filter frame. At least one filter-side mechanical encoding element in integrated in the seal. The at least one filter-side encoding element is a recess in the seal, the recess being a groove, a notch, or a trough. The seal has a reduced height in a region of the filter-side encoding element. The seal is a radial seal.