Navien will be introducing a new Fire Tube Boiler line at the 2018 AHR Expo. The NFB, Navien Fire Tube Boiler, is designed for residential and light commercial applications. Four models will be displayed at AHR: 175,000, 199,000, 299,000, and 399,000 Btuh. The company claims each offers a new patented heat exchanger design, ease of installation and service, intuitive interface, advanced controls, and simplified integration with IoT. Features include a 10:1 turndown ratio, 95% AFUE, flexibility of venting, and remote access via mobile applications.