The NHB (NAVIEN Heating Boiler) Series from NAVIEN is available in four sizes – NHB-55, NHB-80, NHB-110 and NHB-150, with turndown ratios of 7-to-1, 10-to-1, 11-to-1 and 15-to-1. The 15-to-1 turndown ratio in the NHB-150 is achieved with the burner system that includes a dual venturi gas delivery system. They carry the ENERGY STAR 2015 Most Efficient rating and include smart control features that offer an opportunity to achieve a true high-efficiency installation. 800/519-8794; www.navien.com.
