Fogatti FDG-CS120S

The figure of 134 therms of natural gas a year is computed by this site, not by the registry. It is derived from two inputs. One is the registry's UEF, the ratio of hot water delivered to energy used, which is 0.83 for this unit. The other is the DOE test's daily hot-water draw for the medium draw pattern. That pattern stands for a typical three- or four-person household on a busy morning. The figure holds only at that draw and does not describe any other usage. The source is DOE CCD, retrieved 2026-09-19. Figures for other draw patterns are not available on this page.

Among the 80 models registered as a gas tankless unit at the medium draw pattern, this unit ranks 28th lowest at 134 therms. The class median is 135 therms, so the unit sits 1 therms below the median and in the second-lowest quarter of its class for energy use. That gap puts its energy use close to the class median. The figure applies to a household whose hot-water use resembles the medium draw pattern. It says little for a household with much larger or smaller use, because energy at other draws is not available here. To compare units of the same class, use the selector by fuel, space and size or find a same-class replacement by model number.

The running cost is not written here because it depends on your state's average residential gas price. Apply the rate you pay to the 134 therms, or enter your ZIP in the cost calculator on your own ZIP, which does this for you. The method is set out in how the annual cost is calculated. The registry also lists a maximum flow rate in gallons per minute of 3.3 for this unit. That rating is not an input to the 134 therms figure, which comes from the UEF of 0.83. The modeled installed-cost range appears in its own block with its source and date. It is a modeled range, not a quote, and it is not repeated in this text.