Abstract: A method for indicating to a user the expected time for an air purifier to achieve a target level of pollution in a room by: (A) acquiring the current level of pollution (CP) in said room; (B) acquiring current air flow speed (CAFS) through said air purifier; (C) comparing the current level of pollution (CP) with a pre-determined target level of pollution (IP); (D) calculating the expected time (T) required to reduce current pollution (CP) to said target level of pollution (IP) at current air flow speed (CAFS); (E) indicating said expected time (T) required to reduce current pollution to said target level of pollution at current air flow speed to a user; and (F) repeating steps (A) to (E).

Abstract: An air purifier comprising a fan or impeller, an air inlet and an air outlet and a removable particulate filter, the purifier comprising a front panel and a back panel, a first and second opposing side panel between said front and back panels, a base and a top panel, said outlet being disposed along a portion of an edge formed between the top and side panels and also along an edge formed between a portion of said side panels and a portion of said front panel.

Abstract: A domestic air purifier system comprising a removable particulate filter (4), a fan (2) or impeller and which is powered by a motor, an air duct (1) through which air passes in an air flow direction and is purified, and said air duct (1) comprising a duct wall and wherein a portion of said duct wall (1) comprises a gas filter (3) and a method of removing unwanted gases from ambient air by passing over a gas filter in such a system.