SMART VALVES

A Smart Valve is a PICV, supplied with an intelligent actuator, enhancing connectivity. It has the capability to be connected to different sensors, typically temperature and pressure sensors. These sensors allow the monitoring of flow rate, ΔP [the pressure difference between two points], inlet temperature, outlet temperature, ΔT [the temperature difference between two points] and energy consumption. These data points are communicated and viewed through a communication protocol such as BACnet or Modbus [other protocols are available]. Communication protocols also enable remote changes to the writable data points, such as design ΔT and maximum flow rate.

1. With the additional sensors Smart Valves are capable of different control modes. This can be a dynamic control valve with additional monitoring features, a differential pressure control valve, or an energy valve.
   
   
2. Not all Smart Valves are designed exactly in the same way. The main differentiator is howthe flow rate is kept constant with changing differential pressure. There are two main categories: Mechanical Smart Valves and Electrical Smart Valves.

A mechanical Smart Valve combines a mechanical PICV, which uses the three in one valve concept with an intelligent actuator with additional sensors. The intelligent actuator relays the data points from the sensors and any feedback signals to the BMS. When the controlling characteristic is outside of set parameters [which can be altered remotely] the valve position changes. The dynamic feature of a mechanical Smart Valve is achieved by the differential pressure regulator resulting in minimum actuator movements whilst maintaining flow rate pressure independency.

An electronic Smart Valve combines a 2-port control valve with an ultrasonic flow measuring device. The maximum flow rate is set on the 2-port’s actuator. This restricts the maximum opening position, how far the valve can open, irrespective of the control signal.

The ultrasonic flow measuring device (UFMD) measures the flow rate by reflecting ultra-sonic waves off a reflective surface and converting these into a flowrate. If the UFMD senses the flow rate increasing beyond the maximum set point a signal is sent to the actuator on the 2-port control valve and the valve begins to restrict the flow further. Controlling flow rate this way means the actuator is constantly adjusting the valve as the pressures in the system change.

Some manufacturers offer a Smart Energy Valve with a MID-approved UFMD allowing for remote billing. This can be very useful when these valves are used in apartment blocks. Building managers can remotely send e-bills to the apartment’s owners/tenants.