Interpolymers of 1-99 mol % vinyl fluoride and 99-1 mol % of at least one highly fluorinated monomer such as tetrafluoroethylene are disclosed. Water fog is guided into the initial end of an air channel of a stove body, so that the water fog flows through a heat exchange region in the air channel along with circulating air; and the water fog is gasified under a high temperature, so that the circulating air is changed into wet air in the process and carried into a warming space from an outlet at the tail end of the air channel. The motor assembly includes water pumping blades rotatably set at one end of the motor assembly. A metal stack including a layer of silver disposed between layers of platinum is then deposited.