Abstract: There is provided a fan assembly comprising a motor-driven impeller arranged to generate an airflow, an air outlet arranged to emit the airflow, at least one filter assembly that is arranged to purify the airflow, a plurality of sensors arranged to measure a value for each of a plurality of air quality characteristic, and a processor. The processor is configured to receive measured values for each of the plurality of air quality characteristics, identify one of a corresponding set of intervals within which the measured value falls, select an air quality index value associated with the identified interval, and generate a corresponding speed value using the selected air quality index value. The processor is then configured to set a speed of the motor-driven impeller in dependence upon the highest of the speed values.

Abstract: There is provided a fan assembly comprising a motor-driven impeller arranged to generate an airflow, an air outlet arranged to emit the airflow, a plurality of sensors arranged to measure a value for each of a plurality of air quality characteristics, a display and a processor. The processor is configured to receive measured values for each of the plurality of air quality characteristics, identify one of a corresponding set of intervals within which the measured value falls and select an air quality index value associated with the identified interval. The processor is then configured to identify the highest of the selected air quality index values as a current overall air quality index value and to cause the display to display a time series plot of the current air quality index value and a number of preceding air quality index values.

Abstract: A surface-treating appliance, such as a vacuum cleaner, includes a main body housing a component such as a post-motor filter. A door provides access to the filter. The door is connected to the main body by a hinge arranged to allow the door to pivot about the hinge's rotational axis and to move axially as the door is moved between closed and open positions. The provision of a hinge that can move along its rotational axis permits the door to move laterally as it opens, thereby clearing adjacent parts of the appliance, such as the spine. This allows an appliance to be manufactured that permits the user to access components housed inside of it, but is compact. Preferably, the hinge includes a cam arrangement, so that the door automatically moves away from adjacent parts of the appliance as it moves from the closed position to an open position.

Abstract: A surface-treating appliance, such as a vacuum cleaner, includes a main body housing a component such as a post-motor filter. A door provides access to the filter. The door is connected to the main body by a hinge arranged to allow the door to pivot about the hinge's rotational axis and to move axially as the door is moved between closed and open positions. The provision of a hinge that can move along its rotational axis permits the door to move laterally as it opens, thereby clearing adjacent parts of the appliance, such as the spine. This allows an appliance to be manufactured that permits the user to access components housed inside of it, but is compact. Preferably, the hinge includes a cam arrangement, so that the door automatically moves away from adjacent parts of the appliance as it moves from the closed position to an open position.