US Patent 11578885 Air treatment device for a ventilation air inlet

An air treatment device includes a casing with an air inlet and an air outlet. Air flows through the casing and an air treatment section in the casing. The air treatment section includes a fan for generating a flow of air from the air inlet to the air outlet, a filtering means arranged within the flow of air, a first pressure sensor to measure a first pressure in the flow of air, a second pressure sensor to measure a second pressure in a room or cabin surrounding the air treatment device, and a control unit. The control unit is configured to adapt a speed of the fan based on the measured first pressure and the measured second pressure to control a flow of air through the air treatment device.