Open coil elements are the most efficient type of electric heating element while also the most economically feasible for most heating applications. Used predominantly in the duct heating industry, open coil elements have open circuits that heat air directly from the suspended resistive coils. These industrial heating elements have fast heat up times that improve efficiency and have been designed for low maintenance and easily, inexpensive replacement parts.

Open coil heating elements from National heaters are typically made for duct process heating, forced air & ovens and for pipe heating applications. Open coil heaters are used in tank and pipe heating and/or metal tubing. A minimum clearance of 1/8’’ is required between the ceramic and the inside wall of the tube. Installing an open coil element will provide excellent and uniform heat distribution over a large surface area.

Advantages of Open Coil Heating Elements :

In case you’re looking for a product that suits your simple space heating application, you’d better consider an open coil duct heater, since it provides lower kW output.
available in small size compared to a finned tubular heating element
Releases heat directly into the air stream, which makes it run cooler that the finned tubular element
Has a lower drop in pressure
Provides a large electrical clearance
Using correct heating elements on heating applications can help minimize your manufacturing costs. If you need a reliable partner for your industrial application needs, contact us today. One of our customer support specialists will be waiting to assist you.

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 quit 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 strip heater.

The big advantage of open coil heating elements is the very quick response time.

There are standard open coil heating elements available on the market and we carry some in stock. 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.