Presence and Absence Detection Explained

The choice between presence and absence detection for different spaces can make a big difference in user-friendliness and the amount of energy saved.

Presence Detection

Presence Detection
 

Detectors will switch on lighting automatically when a person enters the room, and switches off lighting automatically when no movement is detected.


Absence Detection

Absence Detection

Upon entering the room the person switches on the light as normal, but on leaving the detector switches off the lighting automatically. Lights can also be switched off manually.

 

Presence Detection Absence Detection
Entry – lights on automatically Entry – manually activate lights via a wall switch
Exit – lights off automatically Exit – lights off automatically (can also be switched off manually)

Application

  • Areas which are not generally occupied for long periods of time e.g. toilets, kitchens, copier rooms, hallways etc.
  • Open plan office areas where it is not feasible to use a switch
  • Rooms which are occupied for a longer period of time e.g. offices, boardrooms etc.