A. O. Smith introduces its high-efficiency residential water heater, the Vertex 100 power direct-vent 75-gal. gas water heater. An extension of the state-of-the-art Vertex line, the 75-gal. version is an Energy Star-qualified product and boasts up to 96% thermal efficiency. It also features a long-lasting, energy-efficient supply of hot water, a user-friendly electronic interface and easy installation options thanks to its power-direct-vent to power-vent convertibility.