STATE ATI-180B-N 1**

This site calculates the 206 therms figure; the registry does not list it. The calculation uses the registry's UEF, the ratio of hot water delivered to energy used, and the DOE test's daily hot-water draw for the high pattern. For this model, the UEF is 0.82, as listed in the DOE Compliance Certification Database and retrieved on 2026-09-19. The result reflects the federal test's usage, not metered use in a particular home. Within its class, the model ranks 229th lowest energy use of 397. That places it in the second-highest quarter of its class for energy use. Each step is explained on the page about how the annual energy figure is calculated.

The high draw pattern represents a larger household, or one where showers and laundry overlap. The 206 therms figure applies to homes with that kind of daily hot-water use. A household that uses less hot water would get a different annual figure, and the registry data here does not provide one. The registry also lists a maximum flow rate in gallons per minute of 4.7 for this model. That rating is measured separately from annual energy use and does not change the 229th ranking. To check whether this unit matches a listed class, compare it with gas tankless models at the same high draw pattern. The selector by fuel, space and size groups models that way.

This text does not state a yearly running cost. That cost depends on the average residential gas price in the reader's own state, so the page calculates it from the reader's ZIP. Gas prices differ by state, so no single cost figure would apply to every reader. At any given rate, the 24 therms gap above the class median adds cost in proportion to that rate. You can apply the 206 therms figure to your own rate with the cost calculator for your ZIP. The installed price range has its own block, with its source and date. It is a modeled installed-cost range, not a quote. To look up a same-class alternative by model number, use find a same-class replacement.