STATE ATI-140B-N 1**

This site computes 137 therms of natural gas from the registry's UEF, the ratio of hot water delivered to energy used, and the daily hot-water draw that the DOE test assigns to the medium draw pattern. The registry lists a UEF of 0.81 for this unit, and the DOE CCD record was retrieved on 2026-09-19. The registry itself does not state the annual figure, so treat it as a calculation from those two inputs. It applies only to the medium draw pattern, which represents a typical household of several people on a busy morning. For the method behind the calculation, see how the annual cost is calculated.

Among the 80 models registered as a gas tankless unit at the medium draw pattern, this one has the 52nd lowest energy use. Its 137 therms sits 2 therms above the class median of 135 therms, which places it in the quarter just below the class's highest energy users. That comparison holds only for the medium draw pattern. A household with a different daily draw would need different figures, and this page does not have them. The registry also lists a maximum flow rate in gallons per minute of 3.6; it does not show whether that rate covers a particular household's peak demand. To look at other units in the same class, use the same-class replacement search by model number.

The running cost is not written in the text because it depends on your state's average residential gas price. The cost calculator on your own ZIP applies that price to the 137 therms shown here, at the medium draw pattern. The cost gap between this unit and the class median equals 2 therms multiplied by your gas price per therm. Households whose hot-water use differs from the medium draw pattern should not read 137 therms as their own usage. If you are still comparing fuel, space and size, the selector by fuel, space and size covers that. The installed price range appears in its own block, with its source and date, as a modeled installed-cost range, not a quote.