Air heater

The invention relates to an air heater comprising a cylinder frame and an electric heater with an external wire inside. The invention is characterized in that the cylinder frame contains a ceramic/metal inner cylinder, while thermal insulated material is filled between the inner and outer cylinders, the electric heater is serially or parallel mounted in the inner cylinder, and foam porous ceramic material is filled between the inner cylinder and the electric heater. One end of the inner cylinder is communicated with an air inlet tube while another end is communicated with an air outlet tube, while the air outlet tube is mounted with a temperature controller, and the inner cylinder is packed integrally with the cylinder frame. The invention has high porosity, large specific area, low air resistance, saved energy and high thermal efficiency.