Abstract: An electric heating device has a housing with inlet and outlet openings for a fluid to be heated. The housing has a circulation chamber for passing the fluid to be heated through the housing and a connection chamber for the electrical connection of at least one PTC heating assembly. The PTC heating assembly comprises at least one PTC element strip conductors which energize the PTC element with different polarity and which are heat-conductively coupled to at least one surface of the housing delimiting the circulation chamber. Measures are taken to disturb a laminar boundary layer of the fluid to be heated on at least one of the heat-emitting surfaces. A method is provided for processing at least one heat-emitting surface formed by the housing to provide a structure that disturbs the laminar boundary layer of the fluid to be heated.

Abstract: An electric heating device includes a housing forming a receptacle and a fluid channel The receptable holds a PTC element. In order to reduce weight and assembly effort, the housing is formed by a uniform extruded profile.

Abstract: An electric heating device includes a housing with a partition wall which separates a connection chamber from a heating chamber for emitting heat. At least one heating assembly housing projects from the partition wall in the direction of the heating chamber. The heating assembly housing supports at least one PTC element and strip conductors in an electrically insulated manner A housing wall projecting from the partition wall and delimiting the connection chamber and/or the heating chamber and/or the heating assembly housing is connected to the partition wall by material bonding, which may be by induction soldering. Also disclosed is a method of making an electric heating device.

Abstract: A PTC heating assembly includes a heating cell comprising a PTC element and conductor elements electrically abutting the PTC element. The heating cell is accommodated in a heater housing. The heater housing is manufactured with undersize relative to the heating cell so that the heating cell, after insertion into the heater housing, is held under pretension between mutually opposing walls of the heater housing. Accordingly, in the method according to the invention, the heater housing is elastically widened when the heating cell is inserted into the heater housing.