New Alloy: Inconel® 617 is now available from Alloy Wire. Learn about Inconel® 617

List of Alloys & profiles

List of Alloys & profiles

Surface Area Loading

It is possible to design an element in a variety of sizes all of which would in theory give the desired wattage load or power density dissipated per unit area. However, it is essential that the load on the surface of the element is not too high as the transfer of heat by conduction, convection or radiation from the element may not be rapid enough to prevent it over-heating and failing prematurely.

The suggested surface loading range for the type of appliance and element are shown below – but this may need to be lower for an element working with more frequent operating cycles, or at nearly its maximum operating temperature, or in harsh atmospheres.

ApplianceElement TypeSuggested Surface Loading Range (W/cm2)
FireSpiral Element in Free Air4.5 – 6.0
FirePencil Bar6.0 – 9.5
Band HeaterMica-Wound Element4.0 – 5.5
ToasterMica-Wound Element3.0 – 4.0
ConvectorSpiral Element3.5 – 4.5
Storage HeaterSpiral Element1.5 – 2.5
Fan HeaterSpiral Element9.0 – 15.0
Oven ElementTubular Sheathed Element8.0 – 12.0
Grill ElementTubular Sheathed Element15.0 – 20.0
HotplateTubular Sheathed Element17.0 – 22.0
Water Immersion HeaterTubular Sheathed Element25.0 – 35.0
Kettle ElementTubular Sheathed Element35.0 – 50.0