From: Navien America
Navien’s NPE-A Series condensing tankless water heaters feature: ½-in. gas pipe capabilities; 2-in. PVC venting; dual stainless steel heat exchangers; ComfortFlow recirculation that includes pump and buffer tank; and field gas convertibility. Because up to 16 units can be cascaded together with an external control, the tankless water heater series can be used for residential and commercial applications. The NPE-180A, NPE-210A and NPE-240A are available with on-demand activation and NaviLink Wi-Fi control. If an internal pump and buffer tank are not required for installation, then the company offers its NPE-S standard version.