DF Series

Nagas Innovation DF Series direct gas-fired heaters are designed to heat makeup air, industrial process air, or air consumed by other burners. In buildings where makeup air is required to address negative pressure problems, these high energy-efficient units outperform indirect-fired heaters in bringing makeup air to usable temperatures. 

The Gas Train built in compliance with code B149.3 for site approval.



  • Natural or propane-gas compatible
  • Cast aluminum headers
  • Stainless steel diffuser plates
  • Adjustable profile plate
  • Flame rod detector
  • Sturdy 18 gauge galvanized steel construction
  • Brand name controls


  • Turndown ratio: 30:1
  • Dual air or variable flow to 50%
  • Approved for indoor or outdoor installation
  • 94% efficiency
  • From 90 MBH to 10,000 MBH or higher

Optional Features

  • Controls and gas train enclosure
  • 100:1 turndown ratio
  • FM or IRI gas piping
  • UV flame sensing
  • Industrial NEMA 4 & 12
  • Remote control panel
  • Heated controls
  • All stainless steel construction
  • Custom dimensions
  • Variable air volume down to 25%
  • & more


  • OEM
  • Makeup air systems
  • Industrial laboratories
  • Paint shops
  • Underground parking lots
  • Mechanical workshops, etc.


alt Our direct-fired duct heaters are completely scalable for burner capacity, air flow, or cabinet construction. We can make your requirement happen.
Our very simple, variable-volume burner control dampers can reduce air flow to 25% while maintaining perfect combustion when used with a VFD-driven motor. alt