Fogatti FDG340IN-CS90-LP

The figure of 91 therms is not a registry value. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.84 for this model, and the DOE test's daily hot-water draw for the low draw pattern. The fuel is natural gas, and the source data is the DOE CCD, retrieved 2026-09-19. The figure applies only at that test draw. A home that uses more or less hot water than the test will use a different amount, and measured use in a home is not available in this data. The methodology for the annual calculation sets out the steps.

The unit is compared with the 10 models registered as a gas tankless unit at the low draw pattern. Its rank is 1st lowest energy use of 10, which places it in the lowest quarter of its class. The difference from the class median of 93 therms is 2 therms. The registry lists a maximum flow rate in gallons per minute of 2.3. The data here does not say whether that flow meets the simultaneous demand of a particular home, so that is not available. The figure suits a reader whose hot-water use resembles the low draw pattern. It does not describe a reader whose daily draw is above the test's, because 91 therms would then understate their use. The selector by fuel, space and size covers those other cases.

The running cost is not written in the text because it depends on your state's average residential gas price. The cost calculator applies that price, from your ZIP, to the 91 therms figure for this model. A unit at the class median of 93 therms would use 2 therms more at the same test draw, so the cost gap between the two follows your local price. The installed price range appears in its own block on this page, with its source and date. To compare against another unit in the same class, find a same-class replacement by model number using FDG340IN-CS90-LP.