Ruud PROG29-30U RH63 EC1*

The 185 therms figure 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, with the DOE test's daily hot-water draw for the medium pattern. For this model the UEF is 0.6. Both inputs come from the DOE CCD, retrieved 2026-09-19. Because the figure is tied to the test draw, a household using more or less hot water than the medium pattern would see a different annual total. The registry data does not show how large that gap would be, so it is not available here. The method behind the annual energy and cost figures sets out each step of the calculation.

This model is compared with the 288 models registered as a gas tank at the medium draw pattern. Among them, it ranks 89th lowest for energy use. Its difference from the class median is 0 therms, so its yearly use sits at the middle of the class. The tank has a rated volume of 28 gallons. It also has a first hour rating, the gallons of hot water available in the first hour from a full tank, of 51 gallons. A household whose busiest hour needs more than 51 gallons is outside what this rating covers. A household on natural gas whose peak hour stays within it fits the rating. To compare other units, use the water heater selector by fuel, space and size.

The running cost is not written in this text. The cost of 185 therms of natural gas depends on your state's average residential gas price. The page therefore computes it from your ZIP, and you can repeat that step in the cost calculator for your own ZIP. Because this model's annual energy equals the class median, a unit at the median would use the same 185 therms at the same draw. No installed price range is published for this model. Its ratings lie outside the range that the cost database's model was fitted on. The range is not extended past that limit, so no installed price is shown. To look at other units in the same class, find a same-class replacement by model number.