Abstract: A light tube apparatus includes a tubular housing, a first light source, a second light source, a driver and a controller. The tubular housing having a first light passing window and a second light passing window. The first light source is for emitting a white light from the first light passing window in an illuminating mode. The second light source is for emitting an ultraviolet light from the second light passing window in a sanitizing mode. The driver is for converting an external power source to a first driving current to the first light source and a second driving current to the second light source. The controller is for determining when to enter the sanitizing mode or the illuminating mode based on a stored criterion.

Abstract: An inclined chamber has vertical heating flues on each side thereof. The floors of the heating flues are vertically staggered in an inclined manner. Pairs of heating flues are joined at the tops thereof by guide openings which are vertically staggered in an inclined manner. Central and upper air inlet openings extend into the heating flues and are vertically staggered in an inclined manner.