Air filtering unit

An air filtering unit for filtering air from an indoor setting, the air filtering unit comprising:

• a housing comprising:
• a first indoor inlet air path and a second indoor inlet air path for receiving indoor air, and an outlet for discharge of filtered air, wherein all indoor air entering the housing must flow through the first indoor inlet air path or the second indoor inlet air path in order to reach the outlet;
• an indoor damper arrangement comprising one or more damper elements controllable between at least a first configuration and a second configuration, wherein in the first configuration the first indoor inlet air path is open whilst the second indoor inlet air path is closed to airflow, and wherein in the second configuration the second indoor inlet air path is open whilst the first indoor inlet air path is closed to airflow;
• a first filter device;
• a second filter device, wherein the first filter device has a higher filtering efficiency than the second filter device, wherein indoor air flowing through the first indoor inlet air path is directed through the first filter device and indoor air flowing through the second indoor inlet air path is directed through the second filter device;
• a controller for controlling the indoor damper arrangement;
• wherein
• the controller is configured to communicate with a building management system or a smartphone app and the controller controls the indoor air damper arrangement responsive to instructions received from the building management system or smartphone app;
• and/or
• the air filtering unit further comprises an indoor air quality sensor for obtaining a measurement relating to indoor air quality within the indoor setting, wherein the controller controls the indoor air damper arrangement responsive to the measurement such that when the measurement indicates that the indoor air quality is below a predetermined level, the controller is configured to place the indoor damper arrangement in the first configuration, and when the indoor air quality is above the predetermined level the controller places the indoor damper arrangement in the second configuration.