Subhot Industrial

Duct Heater

Duct heaters are heat transferring devices which are an assembly of heating elements mounted in a frame or duct. Preferably used for non-pressurized air-heating systems, there are three types of duct heaters available: open coil, tubular or finned tubular heating elements that are either flanged or inserted in the duct.
If any application needs a very large capacity of heat duty, then bundle of several smaller duct heaters can be made & assembled in series.

The individual elements are removable through the housing of the assembly, which eliminates the need to pull the complete heater from the ductwork. This reduces downtime costs because the heating elements can be replaced individually.

Being the most easily adaptable heating solution, they are easily installed in applications requiring a wide range of temperature versus air flow combinations and offer greater reliability, energy efficiency, quicker response time and reduced infiltration from the air steam.

Duct heaters can be equipped with a temperature control system and wired in various power configurations.

Sheath MaterialSteel, Copper, Stainless Steel, INCOLOY
Heating ElementTubular, Finned and Open Coil
Watt DensityUp to 40 W/in2
WattageUp to 2 MW
ControlsSSR/ SCR/ Digitally Controlled
Diameter of Tube0.260, 0.315, 0.375, 0.430, 0.475 (inches)
Voltage120, 240, 300, 480, 600
Sheath Length11 – 240 inches
Process Temperature-29°C to 650°C
Wattage Tolerance+5%, -10%
Resistance Tolerance-5%, +10%
  • 1. Heat treating
  • 2. Air drying operations
  • 3. Air handling equipment
  • 4. Comfort air heating (HVAC)
  • 5. Core drying
  • 6. Fan coils
  • 7. Booster air
  • 8. Air preheating
  • 9. Terminal reheating
  • 10. Multi zone reheating
  • 11. Resistor load banks
  • 12. Annealing
  • 1. Energy efficient.
  • 2. Corrosion and oxidation resistant.
  • 3. Quite easy to mount.
  • 4. Durable and easy maintenance.
  • 5. Rugged construction eliminates hazard of electric shock.
  • 6. Reinforced frame allows for minimum vibration.
  • 7. Minimal heat loss.