Open Coil Air Heating Elements for Convection, Duct & Oven Heating
Open Coil Heating Elements-Description Guide:
Open coil heating elements are coiled resistance wire fixed onto a supporting steel or aluminum frame with
ceramic insulators. The selection of the correct wire gauge, wire type and coil diameter requires quite some
experience. There are standard elements available on the market, but quite often they need to be custom
built. Open coil air heaters work best below air velocities of 80 FPM. Higher air velocities could cause the
coils to touch each other and short out. For higher velocities, select a tubular air heater or finned tubular heaters.
Review General Applications:
The big advantage of open coil heating elements is the very quick response time. Most of these elements
need a constant airflow over the resistance wire, but if the watt densities are low enough they may not
burn out in still air.
Nichrome resistance wire open coil elements are used extensively in convection heating applications,
R&D and as replacement coils in duct heaters, portable heaters and air process heaters, as well as in
some infrared applications such as vacuum forming /thermoforming.
Before we can build a heater, we need to know at least the airflow (CFM), Delta T ( i.e. change in temperature),
volts and watts.
Features & Benefits:
Quick heat up time & easily replaceable
Outside diameters: 1 7/8'' and 2 ¾''
Lengths: 60-320'' (5-26 ft)
Single element ratings: 4-20 kW
Pipe Surface: 3-12 W/In2
Voltages: 240, 480 and 600V, 3 PHASE
Used in horizontal 2'' or 3'' schedule 40 NPS pipe
Equipped with high density electrical ceramic insulating supports
Can be bent in a vertical plane on at least 12'' radius
Heavy gauge bus bars
Heavy gauge resistance wire
Special ratings and lengths available upon request