RDFF - Commercial Flanged Duct Heater Flanged Duct Heater

The Ruffneck™ RDFF Commercial Flanged Duct Heater with finned tubular (Calrod® type*) elements is designed for use in comfort heating applications, such as make-up air heating, air pre-heating, air handling equipment, fan coils, terminal reheating, multi-zone reheating, heat pump auxiliary systems and return air heating. The finned tubular elements are constructed using a steel tube with a corrugated steel fin wrapped around it and brazed together, which increases the heat transfer surface of the element resulting in a lower operating temperature than the non-finned tubular element designs.


  • Certified for use in ordinary (nonclassified) locations
  • Designed for use in commercial comfort heating applications
  • Finned tubular element increases heat transfer surface area resulting in lower operating temperature
  • Primary and secondary cutouts for overheat protection are standard on all models


primary linear cutout, 160°F (71°C), 277/600 VAC, 25/10 AMP non-inductive
secondary linear cutout, manual reset complete with backup magnetic contactor on units under 300V, 30 kW and less, 225°F (107°C), 277/600 VAC, 25/10 AMP non-inductive
a wide range of optional auxiliary duct heater controls available either as factory installed on the duct heater or as an EEMAC rated control panel for wall mount, including bulb holders, silent contactors, SCR controllers, switches, magnetic contactors and more
models range from 1-120kW and up to 600V, 3 phase
frame fabricated from 16-gauge satin-coat steel
approved for horizontal duct installation where maximum inlet air temperature does not exceed 25°C (77°F) and maximum rating does not exceed 120 kW
CSA C/US & CE approved; GOST approved for global markets