The Pennant line of fan-assisted, modular boilers and water heaters ranks among the industrys most versatile and environmentally friendly commercial systems for hydronic and hot water applications. Available in 7 sizes from 500 to 2000 MBTU/h, Pennant boilers and water heaters run reliably on natural or LP gas and deliver efficiency levels up to 85%. Pennant systems are also among the greenest in the industry with NOx emissions below 10 ppm.