Patent ID: 7676144

Claim:
A heating device for heating air, the heating device comprising: a frame defining an external perimeter of the heating device; multiple heat-generating elements housed within the frame, each of the multiple heat-generating elements comprising: at least one PTC element; electric strip conductors lying on opposing side surfaces of the PTC element; and multiple heat-emitting elements that are arranged in parallel layers and, lying on opposing sides of the heat-generating element, that are held in position, wherein each of the heat-emitting elements fits against the opposing sides of the heat-generating element with an insulating layer in between, wherein the insulating layers electrically insulate the electric strip conductors from the heat-emitting elements, mitigating any electrical potential between respective ones of the heat-emitting elements during high voltage uses; and a spring contained within the frame and holding the multiple heat-generating and heat-emitting elements in a state of initial tension within the frame.