Presence and motion detectors "see" using a passive infrared sensor that detects heat sources. A motion detector measures the heat of moving objects, checks the light level and switches on lighting if the measured light intensity is below a set threshold value. Following a time interval programmed on the timer, the detector then switches the lighting off again. Presence detectors are only functionally different in that they measure light continuously. This allows the detectors to switch artificial lighting on or off based on the daylight. Presence detectors are thus best suited for use in rooms where people spend large periods of time, while motion detectors deliver brief periods of illumination.
It's obvious that needs-based lighting control lowers energy consumption. At one time or another, we've all caught ourselves forgetting to turn off the lights when leaving the room. What is merely annoying on a small scale, however, adds up in the big picture. A brightly lit hallway creates a feeling of security, and the right level of working light in the office is beneficial to health and the ability to concentrate – but only when the hall and office are actually being used! In some cases, such as in public parking garages, lighting is mandatory. To meet this need, the talis product range includes a presence detector which provides reduced base-level lighting as needed. Using a remote control, this lighting can be adapted in increments to fit the current situation. The potential energy savings offered by intelligent lighting control can be the deciding factor in determining a building's energy efficiency class rating.
Compared to energy savings, security is often a secondary aspect, even though it also has an impact on cost. A hotel hallway that is dimly lit in order to lower energy costs scares away guests (especially females), just as a poorly lit mall parking garage can drive away customers. And in the case of an accident, insufficient parking garage lighting promptly becomes an (insurance) issue. Intelligent lighting control helps increase both safety and energy-efficiency. Visibly installed presence and motion detectors also have a preventative effect: They deter unwanted visitors and are therefore frequently used outdoors and in traffic areas. For offices and other interior spaces, the best choice is a flush-mounted unit. Invisibly integrated into the ceiling, these detectors blend into the existing architecture.
Intelligent lighting control makes life easier: Whoever enters a room with a stack of files balanced on his/her arm or attempts to leave the garage at home with shopping or grocery bags will appreciate the hands-free operation of light switches. And upon closer inspection, this convenience argument also contains a security aspect.