With Navien’s unique and proprietary heat exchanger design the NPE-S is able to achieve the industry leading 0.99EF / 0.97 UEF.
Navien’s unique condensing heat exchanger design uses heat from the flue gases to preheat the water in the most efficient way available today. This design requires less input to achieve a higher output than a comparable tankless water heater. That means savings on gas and a better performance. For example, a NPE-210S with an input of 180,000 BTU/H has a higher output (~178,000) than a non-condensing 199,000 BTU/H unit with an output of ~163,000.
With Navien’s condensing technology, you get the best of both worlds: the best value and “ultra condensing efficiency”, which offers substantial savings and contributes to a green-friendly environment. Plus, the installation and venting processes are easy, cost effective, and Navien’s products are simply the best in quality and performance.