Taco Zone Sentry Zone Valves provide on-off, normally open or normally closed control in both open and closed hot or chilled water systems. The valves can be used in a wide variety of heating and cooling applications, primarily designed for use with fan coils, radiators, convectors, air handlers, heat pumps and radiant applications. Savings and efficiency are what the Zone Sentry is all about. Using patented technology and microcircuit-based logic, it draws just 1.44 watts when its ON, and is expandable to up to 12 zone valves per standard 40 VA transformer, saving on components. The Taco Zone Sentry Zone Valve enhances the overall performance of any zone valve system. The unique patented technology in the Zone Sentry utilizes a microcircuit based logic to control a gear driven electronic actuator which drives a ball valve based body design. All this adds up to a zone valve that leads the industry in energy efficiency, flow capacity (Cv), shutoff pressure rating, ease of installation, diagnostic capability and the number of valves (12) that can be use on a standard 40VA transformer.