The ENERGY STAR® Qualified A. O. Smith high efficiency condensing XP Water Heater utilizes a state-of-the-art heat exchanger and control technology to provide large volumes of hot water for demanding commercial and industrial potable hot water applications. The all stainless steel heat exchanger and modulating combustion combine to deliver up to 96% thermal efficiency. XP models rangein size from 150,000 to 800,000 Btu/hr to fit many needs. XP water heaters vent in inexpensive PVC/CPVC pipe and can also be vented in AL29-4C® when specified or required by local codes. All XP models are fully modulating with turndown rates of up to 5:1.