ENVO WH-AZ02-199-NGI

This site calculated the 209 therms figure; the registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, which is 0.81 for this model. It also uses the daily hot-water draw that the DOE test sets for the high draw pattern. The UEF comes from the DOE CCD registry, and the data on this page was retrieved on 2026-09-19. The figure holds only at that test draw; a home drawing more or less hot water daily will use a different amount. The page on how the annual cost is calculated explains how these inputs feed the yearly figures.

The 323rd ranking above means this model sits in the highest quarter of its class for energy use. The class is the 397 models registered as a gas tankless unit at the high draw pattern. At the same test draw, most units in that group would use less gas than the 209 therms shown here. The high draw pattern fits a larger household, or one where showers and laundry overlap. For that kind of home, this unit's maximum flow rate in gallons per minute is 4.9. The registry data here does not show how that flow compares with the rest of the class. This model does not meet a target of gas use below the 182 therms median at this draw pattern. Readers with that target can find a same-class replacement by model number.

Running cost is not stated in this text, because it depends on the reader's own gas rate. The cost calculator on your own ZIP computes it from your state's average residential natural gas price. The input is the 209 therms yearly figure, so the result holds only at the federal test's daily draw. At a given gas rate at the high draw pattern, this model's cost exceeds the class median's by the price of 27 therms. The installed price range appears in its own block, with its source and date, as a modeled range rather than a quote.