AIR HEATER
Air heater comprising a gas burner (1) and heat-exchange means (2) including at least one heat-exchange wall which separates a first passage (5) for flow of air to be heated from a second passage (6) for flow of the flue gases produced by the burner (1), the air to be heated being made to flow by blower means through the first passage (5), the hot flue gases flowing in counter-current through the second passage (6), wherein the burner (1) is of the radiation type, and the heat-exchange wall comprises a convective-exchange part and an absorption part for absorbing the radiation from the burner, the flue gases heating the air by convection mainly in the region of the convective-exchange part, the radiation from the burner (1) being mainly emitted towards the absorption part, the air flowing over this absorption part after it has flowed over the convective-exchange part.