Air duct heater

Air Duct Heater for HVAC Systems

What is an air duct heater?

Air duct heater are assembly of heating elements that are intended to use in air handling and conditioning systems. They are utilized to warm streams of air or gases in circulation. Furthermore, duct heaters are heat-transfer devices composed of heating elements mounted in a frame or duct. Air duct heaters are classified into two types: tubular heaters and finned tubular heaters. A bundle of several smaller duct heaters can be made and assembled in series for high heat duty in specific applications. They are primarily used for heating, ventilation, and air conditioning (HVAC), although they can also be helpful for drying or preheating solid objects.

Areas separated from the main HVAC unit might experience inadequate air conditioning and heating. The solution is Marathon heater’s duct heaters, which provide enhanced comfort and system efficiency by maintaining or accelerating warm air flow throughout a structure’s ductwork. Marathon Heater manufactures air duct heaters that can heat new or recycled air up to 650 °C and have customizable power as well as voltage ratings based on the customer’s needs.

Applications of Air Duct Heaters

  • Heat treating as well as conditioning
  • Multi-zone reheating
  • Heating, ventilation, and air conditioning (HVAC) in industrial and residential buildings
  • Industrial hot air generation
  • Drying of air in power plants
  • Automotive industry
  • Air drying as well as handling operations


  1. Terminal Box– It comprises all of the heating element terminals and is internally wired into groups.
  2. Heating Element– Two types of heating elements are available:
    • Tubular heating elements: They can withstand high temperatures and are made of stainless steel or alloy sheath that prevents oxidation and corrosion.
    • Finned Elements: Tubular heaters with circular fins enclosed around the active length. Attached fins increase the heat transfer area, resulting in a faster heat transfer rate.
  3. Mounting Flange/Plate– The heating elements are attached to this plate, which will be fixed to the duct’s external body.
  4. Baffle plate- To support and hold the heating elements while at the same time minimizing vibrations.
Construction of air duct heater

Features and Benefits

  • Adaptable as well as cost economical.
  • Corrosion as well as oxidation resistant.
  • It is quite easy to mount.
  • Power control system such as an SSR or an SCR.
  • Rugged construction eliminates the hazard of electric shock.
  • A reinforced frame allows for minimum vibration.
  • Minimal heat loss as well as energy efficient.

In conclusion, Marathon Heaters’ duct heaters are specifically designed and built for OEM drying and heating processes. We can also supply a power and temperature control panel, as well as temperature sensors, for precise operation and control. Watch our video to find out how the air duct heater works: