The Rheem 29-gallon XR90 Extreme Recovery gas water heater heats water 42% faster than a standard 50-gallon gas water heater. The Energy Star-qualified unit uses a proprietary baffle and flue design that retains the burner’s heat longer, so the XR90 is able to transfer more heat to the stored water. As a result, the byproducts of the combustion process are drawn through the flue with a 110-VAC, fan-assisted draft inducer, powered by a standard household current.