AMERICAN ATI-140B-N 1**

The figure of 137 therms is computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.81 with the daily hot-water draw that the DOE test assigns to the medium draw pattern. The registry data was retrieved from the DOE CCD on 2026-09-19. The listed maximum flow rate in gallons per minute is 3.6. That value describes capacity and is not an input to the annual energy figure. The arithmetic is set out in the page on how the annual cost is calculated. The figure applies only to the medium draw pattern, and this page has no value for any other pattern.

The model is compared with the 80 models registered as a gas tankless unit at the medium draw pattern. It ranks 52nd lowest energy use, and its 137 therms is 2 therms above the class median of 135 therms. That places it in the second-highest quarter of its class for energy use. The comparison suits a household whose daily use matches the medium draw pattern and who wants to check this unit against its peers. It does not describe a household with a different daily draw, because the data here does not show this model at other draw patterns. To compare against other models in the same class, use the same-class replacement search by model number.

The running cost is not stated in the text because it depends on your state's average residential gas price. Enter your ZIP in the cost calculator for your own ZIP to apply that price to 137 therms. The result holds for the medium draw pattern only and rests on the 0.81 UEF from the registry. The modeled installed-cost range appears in its own block with its source and date, and it is not a quote. If the fuel, the available space or the household size differs from this listing, the water heater selector by fuel, space and size covers those cases. The registry data does not say how this model performs in your home.