LOCHINVAR HESF-40 1**

The 3,531 kWh figure is computed by this site. The registry does not publish 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 medium pattern. For this model, the UEF is 0.92. The medium pattern represents a typical three- or four-person household under the federal test. The registry data comes from the DOE CCD and was retrieved on 2026-09-19. At a different daily draw, the yearly figure would change. This page has no value for any other draw pattern. The steps are set out on the page explaining how the annual cost is calculated.

Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 64 gallons. The rated volume is 37 gallons. These two figures, not the energy figure, show whether the tank can meet a household's peak demand. A household whose busy morning fits the medium pattern matches the condition behind 3,531 kWh. A household that needs more than 64 gallons in its busiest hour falls outside what this rating covers. That household's yearly energy use would also differ from the published figure, by an amount not available here. To check units with a different fuel, space or size, use the selector by fuel, space and size.

This page does not state a running cost, because the cost depends on your own utility's electricity tariff. The cost calculator on your own ZIP applies your rate to 3,531 kWh a year. In its class, the model ranks 213th lowest of 426 for energy use. This places it in the second-lowest quarter of the class, even though its figure equals the class median of 3,531 kWh. On the same tariff, its computed running cost at the medium pattern would equal that of a model at the class median. The installed price range appears in a separate block on this page, with its source and date. That range is modeled, not a quote.