Are zone valves considered operating controls in hydronic systems?

Zone valves indeed function as operating controls in hydronic systems. Their primary role is to regulate the flow of hot water to specific zones or areas within a building based on the demand for heating. By opening or closing in response to the temperature needs of individual zones, zone valves help maintain the desired temperature efficiently. This targeted control helps optimize energy use, as the system only heats the spaces that require it, rather than providing consistent heat throughout the entire system.

In a hydronic heating system, the operation of zone valves is typically integrated with a thermostat in each zone. When the thermostat detects that the temperature falls below a set point, it activates the zone valve, allowing hot water to flow to that zone, thereby heating it. Conversely, when the desired temperature is reached, the valve closes, stopping the flow of water. This operation is key for comfort and efficiency, making zone valves a critical aspect of the control system in hydronic applications.