Automation of lighting, HVAC, and shades in response to changing conditions in an office or a home is essential for creating a complete energy management solution. While it provides amazing levels of convenience and comfort, it is also offers a solution to avoid employee friction caused when energy policies are implemented strictly.

In the past we have talked about daylight sensors and their role in automating energy management. Occupancy sensors are another tool available to lighting designers, and work by automatically turning off the lights when a room is unoccupied.

One such occupancy sensor is Crestron’s GLS-ODT-C-CN, which is a low-profile ceiling mounted unit designed for large areas up to 2000 square feet. This is an ideal solution for reliably detecting when someone is present in large spaces like auditoriums, warehouses, and building lobbies.

The Crestron GLS-ODT-C-CN offers the following key features: 

Dual-Technology Occupancy Sensing: To achieve consistent and dependable occupancy sensing this unit uses a combination of ultrasonic and passive infrared technologies. The ultrasonic motion detection achieves high sensitivity to small movements over a large area, while passive infrared ensures superior immunity to false triggering from vibrations, inanimate objects, or movement in an adjacent corridor. Ultrasonic motion detection can be turned on for Side A, Side B or Both sides of the occupancy sensor to avoid false occupancies facing a hallway or doorway.

Walk-through mode: This sensor features a walk-through mode that is very useful in brief occupancy situations, by turning lights off quickly when someone enters and exits the room within a period of 90 seconds.

Grace occupancy Feature: When the lights turn off in a room programmed to vacancy only mode, a 15-second grace period allows room lights to be turned back on by simply waving a hand to trigger the sensor.

Ambient light recognition: A built-in photocell allows detection of ambient light and can override the occupancy sensor if the light levels are sufficient. This reduces unnecessary energy consumption and performs daylight harvesting and dimming (via programming) when appropriate.

Versatile installation: The GLS-ODT-C-CN has a discreet, nearly hidden appearance when installed on a typical drywall or droptile ceiling. Hardware is included for fast and simple mounting in a hole created by the provided cutout template or to a standard 4-inch octagon box.

Other features of this occupancy sensor are:

Ceiling-mount occupancy sensor

360 degree, 2000 square feet coverage

Discreet, low-profile appearance and fully digital circuitry for high reliability

Built-in ambient light recognition and external photo sensor input

Control system integration interface

For more information on Crestron’s power saving and energy management solutions, visit their website at

(Image credit:

AV Solutions, Audio Visual Consultants at Actis Technologies India