An apparatus is provided for rotating heated air in a chamber (16) adapted for receiving a heat source (36). The apparatus has a gas inlet opening (24, 26, 30) and a gas outlet opening (32), wherein the gas inlet opening (24,26,30) and the heat source are located in a lower area (12, 20') of the chamber (16) and the gas outlet opening (32) is located in an upper region (14) of the chamber (16) so that, when a heat source is placed in the chamber (16), an ascending gas flow may be generated in the chamber (16). The chamber (16) tapers inwardly from bottom to the top and that the gas inlet opening (24, 26, 30) is formed so that inflowing gas flows therethrough in a directed manner along a directional vector into the lower area (12, 20') of the chamber (16) such that a substantial component of the direction vector projects along an inner wall of the chamber and follows an at least approximately circular path along the inner wall in a common rotational sense around the heat source and then is drawn upwardly by a draw of the ascending gas flow along an approximately spiral path and then though the gas outlet opening (32). A cylindrical liner (220) is rotatably displaceable about the central axis (A-A) of the apparatus and includes at least one blocking portion (222) which, when the liner is selectively rotated about the central axis, selectively blocks the air flow through an adjacent channel (24, 26, 30). Further, a candle assembly is provided having at least one wick, the candle assembly formed of at least two wax parts which interface together to allow selective juxtaposition of wax parts having desired color combinations, scents, and wax compositions. The parts, when fit together conform to in inner form of a receptacle, and are held together with the at least one wick in such receptacle. Optionally, at least one part has a recess into which the at least one wick may he held in place or positioned to facilitate accurate assembly.