Change-Over Sensor

The RICKARD Reversing Changeover facility ensures that the VAV diffuser controls the temperature accurately in both heating and cooling mode i.e. when the central system is supplying either warm or cold air.

When the system switches from cooling to heating mode, the changeover sensor detects the increase in supply air temperature and switches the direction in which the actuator operates.  This means that when the system is in cooling mode, the diffuser will drive open as the room temperature increases, whereas in the heating mode the diffuser will close as the room temperature increases.