LOCHINVAR ATO-140B-N 1**

This site computed the 137 therms figure. The registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw. For this unit the UEF is 0.81, taken from DOE CCD data retrieved 2026-09-19. The medium draw pattern represents a typical mid-sized household on a busy morning. If a home uses more hot water than that test day, its yearly use will be above 137 therms. If it uses less, its yearly use will be below that figure. The inputs and steps are listed on the page about how the annual energy and running cost are calculated.

Within its class, this unit ranks 52nd lowest in energy use out of 80 models. Its 137 therms is 2 therms above the 135 therms class median. That puts it in the upper half of its class for energy use but outside the highest-use quarter. Its maximum flow rate in gallons per minute is 3.6. That is the most hot water it can deliver at one time. It fits a household whose daily use is close to the medium draw pattern and whose peak demand stays within 3.6 gallons per minute. It fits less well if the goal is gas use below the class median, because a rank of 52nd lowest means most models in its class use less gas. To look at other units in the same class, use the same-class replacement search by model number.

This text does not state the running cost of 137 therms of natural gas. The cost depends on your state's average residential gas price, and this page does not assume one. Instead, the page works out the cost from your ZIP, using the same 137 therms at the medium draw pattern. The cost of the 2 therms gap to the class median also depends on that rate. To see the figure for a different location, use the water heater cost calculator for your own ZIP. The installed price range is shown in its own block, with its source and date. It is a modeled installed-cost range, not a quote, and this text does not repeat it.