A fan assembly (10) includes a housing (20) with an air inlet (70), a fan inlet (60), and an air outlet (80). The fan assembly further includes an impeller (30) and a motor (40) configured to drive the impeller, the impeller having a plurality of circumferentially positioned spaced blades (34). An air-permeable guard (50) is positioned between the air inlet and the fan inlet to prevent users from touching the impeller (30), and is spaced a first distance (54) from the fan inlet (60), and a second distance from the air inlet (70) so that a filter (90) may be provided between the air inlet (70) and the air-permeable guard (50). Preferably, the first distance (54) is such so as to allow incoming air to at least partially rotate prior to entering the fan inlet. Preferably, the plurality of circumferentially positioned spaced blades (34) is positioned circumferentially around a domed center (32) of the impeller (30), the domed center (32) facing the fan inlet (60), and the domed center (32) co-rotates with the spaced blades (34).