Navien's NPN series is the first and only non-condensing tankless water heater series that offers a durable stainless-steel heat exchanger and a patented stainless steel burner design, all with Navien's dedication to advanced engineering, elegant design, exceptional product quality, customer support, and strong warranties. The NPN-E models are designed exclusively for external installation. Other features include:
- Up to a 0.81 Uniform Energy Factor
- 98°-140° temperature range
- Up to 9.5 GPM at a 35° temperature rise
- Cascade capable for up to 2 uints
- Uses NaviVent concentric 3" x 5" venting