Navien’s NPE water heater series expands with the addition of the NPE-150S model. This smaller size “S”, standard version, with an Energy Factor of 0.97, has a heating capacity of 18,000 to 120,000 Btu/hr. and will produce 5.3 gal. per min. at 45° temperature rise. It features 1/2” gas pipe capability, 2” PVC venting up to 60’, dual stainless-steel heat exchangers, an integrated and easy-to-use control, field gas convertibility, and cascade capability without an external control.