The outer surface of a finned heating element is considerably larger in relation to traditional metal sheathed tubular heating elements of the same length, thus allowing for a considerable reduction of the surface load and extension of the heater’s life.
The fins are attached to the heater’s stainless steel tube of 8.5 mm diameter. There are two types of finned heaters:
Wound stainless steel strip, outer diameter = 25 mm.
Aluminium formed ribs – outer diameter: = 28 mm.
Symbols: D – fins’ diameter ; d – heating element’s diameter (Ø8.5mm) ; T – fins’ spacing – higher for convection heaters and lower in case of forces air flow.