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The Presence Detectors and the Absence Detectors explained, energy saving solutions

  2010-03-01         admin         Product News » Lighting News
We have previously introduced many energy saving solutions like the time lag switches and the presence detectors (PIR detectors, energy saving solutions, the time lag switches, PIR and time lag switches, wall mounted presence detectors, etc), so we feel that we need to explain WHAT ARE these presence detectors and what are the absence detectors, what is the difference, etc. Via CP Electronics, we found some pertinent information which we would like to share with you. But first of all, Why do we need to control energy consumption? The need to control lighting, heating and ventilation in commercial, professional and domestic buildings is becoming more important than ever. There are many reasons why we should all aim to reduce energy consumption within our buildings including:
  • the rising cost of energy;
  • the pressures to reduce operational costs and become ever more competitive;
  • our obligation to reduce our carbon footprint and environmental impact;
  • the need to reduce our consumption to prolong fossil fuel supplies;
  • to comply with environmental legislation for new and existing buildings.

The Presence Detectors - energy saving solutions

The presence and the absence detectors provide automatic control of lighting, heating and ventilation. At the same time, the presence / absence detectors can help you reduce energy consumption by automatically turning off lighting, heating or ventilation that is needlessly left on. They can also contribute to public and workforce safety by automatically illuminating dark corridors and stairwells, for example.
The presence detectors can help you meet energy reduction targets in new and existing buildings
The wide range of presence detectors found at - at the Energy Management section - are designed to reduce the amount of time lighting is left on unnecessarily(for example if an area is unoccupied or if there is sufficient natural light). A presence detector monitors the detection zone for occupancy; if a person is detected/sensed then the detector will automatically turn the lighting on. When the area is vacated/no one is sensed in the perimeter, the lighting will turn off after a preset time delay. Most of the presence/absence detectors have a built in light level (lux) sensor which will keep the lighting off if there is enough natural light available.
  • When you are controlling the lighting with a presence detector you can save up to 60% of lighting energy costs depending on the occupancy behavior and the amount of the natural light available.
  • In the range of presence detectors found on our website you are sure to find a presence detector that will suit any area. We have a wide range of PIR (Passive InfraRed) presence detectors which detect body heat and movement and are ideally suited to smaller spaces or where a defined detection pattern is required.

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. See below what are the Presence Detectors / the Absence Detectors and where to use them.

Presence Detection

  • The presence detectors will switch on the lighting system automatically when a person enters the room/perimeter monitored, and it also switches off the lighting automatically when no movement is detected.
  • Applications: Energy saving and cost effective, can be used instead of a conventional switch(they can replace the normal switches).

Absence Detection

  • The Absence detectors - 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.
  • Applications: Commonly used for improved energy saving and to comply with regulations.

If you have any questions or comments related to this topic, do not hesitate to leave us a comment.