Navien launches fire tube boiler series: NFB-C

20 November 2019

Navien, the condensing wall-hung boilers company has officially launched their commercial-sized fire tube boiler series, the NFB-C. The NFB-C is available in two sizes: NFB-301C (301 MBH) and NFB-399C (399 MBH).

Each NFB-C boiler uses the same in-house designed and manufactured patented heat exchanger technology that was introduced with the NFB series in 2018. The heat exchanger is form-pressed and robotic laser welded to minimize the number of weak points that could be prone to thermal stress and corrosion. Oval shaped tubes within the heat exchanger contain internal turbulators designed to improve both the heat transfer rate and the structural integrity of the assembly. A specific water flow is generated by baffles to extract the maximum amount of heat from flue gasses while the non-metallic base provides additional protection against corrosion caused by acidic condensate.

The 97.5% thermal efficiency NFB-C series includes top and bottom piping connections for installation flexibility. The NFB-C series commercial fire tube boilers offer up to a 15:1 turndown ratio and extremely low NOx levels, certified by SCAQMD to meet the most stringent code requirements.