The NCC1991 condensing tankless water heater fromNoritz America delivers a thermal efficiency of 94% with an input range of 16,000 to 199,900 Btu. This enables the unit to meet the needs of a variety of commercial projects. Using a special Quick Connect cable, two NCC1991-DV units can be coupled to provide an input of nearly 400,000 Btu with a turndown ratio of more than 36:1. This makes the NCC1991 ideal for applications where hot-water demand can substantially vary over time.Noritz condensing tankless water heater