Company: Navien Inc.

Product: NFB Fire Tube Boilers

Description: The NFB series is available in two models: NFB-175 (175,000 Btuh) and NFB-200 (199,900 Btuh), each featuring a patented fire tube heat exchanger. Designed in-house, it 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 inside the heat exchanger to extract the maximum amount of heat from flue gasses, while the non-metallic base provides additional protection against corrosion caused by acidic condensate. Additional features include advanced user interface controls, built-in zone controllers, 10:1 turndown ratio from a sophisticated gas flow control system, field gas convertibility, low NOx levels, cascade capability up to 16 units, common venting capability up to eight units, and remote accessibility when installed with NaviLink™ Wi-Fi control system.