Vertex, a 76,000 BTU power-vent residential gas water heater is equipped with 90% thermal efficiency. Vertex was developed by A.O. Smith in partnership with TIAX, LLC, a design engineering firm, as part of a U.S. Department of Energy program. Vertex will deliver significant savings on operating costs compared to standard 78% efficient water heaters, the company said. With an estimated 127-gallon first hour delivery and 93 GPH recovery, the hot water capability of Vertex rivals that of a conventional 75-gallon tank-type unit. Vertex can be installed as part of a combination space heating/water heating application, radiant floor heating system or any system requiring a recirculating hot water loop. It has an internal “helical coil” heat exchanger with increased surface area exposed to water in the tank.