To properly match a duct heater to an application, the wattage, air velocity and element watt density must be determined.
Formulas and graphs that will aid in your design include:
- Wattage calculation formulas and table
- Element Watt Density vs. Sheath Temperature and Air Velocity Graph
- Pressure Drop vs. Air Velocity Graph
In most applications the following design limitations should be adhered to:
- Maximum watt density of 40 watts/in2 (6.2 watts/cm2 )
- Maximum element sheath temperature of 1400°F (760°C)
- Minimum air velocity of 200 feet per minute (61 meters per minute)
- Maximum voltage for UL certified heaters is 480V.
- Maximum voltage for CSA certified heaters is 600V.
Eagle Sensors & Controls is an authorized Tempco distributor. Contact us for sales and application support.