Mizudo FDG-CS120S

The figure of 134 therms is computed by this site, not published by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.83 with the daily hot-water draw that the DOE test assigns to the medium draw pattern. The source is DOE CCD, retrieved 2026-09-19. The figure applies to natural gas and to that draw pattern only. A household that draws more or less hot water than the test day will use a different amount. The registry also lists a maximum flow rate in gallons per minute of 3.3. That is a capacity rating and does not change the annual figure. The steps are set out in how the annual cost is calculated.

Among the 80 models registered as a gas tankless unit at the medium draw pattern, this one ranks 28th lowest for energy use, which places it in the second-lowest quarter of its class. Its 134 therms sits 1 therms below the class median of 135 therms. The data on this page does not show how the models next to it in rank differ from one another. The figure suits a reader who wants to confirm a listing or compare against a unit of the same class, and a same-class replacement by model number can be looked up separately. It does not describe a household whose daily hot-water use differs from the medium draw pattern. Registry values for other draw patterns are not available on this page.

The running cost is not written out here because it depends on your state's average residential gas price. To estimate it, multiply 134 therms by your own price per therm, or use the cost calculator on your own ZIP. Either result holds only for the medium draw pattern; a different daily draw changes it. The modeled installed-cost range appears in its own block with its source and date. It is a modeled range, not a quote, so it is not repeated in this text. If fuel type, available space or household size differ from this listing, the selector by fuel, space and size covers those conditions.