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Real-time occupancy monitoring of the comings and goings inside a warehouse, conference room, or corridor yields valuable data. That data can be sent to the Cloud for deeper analysis and strategic decision-making on occupancy issues such as enhanced building security, personnel safety monitoring, and sustainable lighting and HVAC use.
Better productivity and planning
System managers can maximize space usage and boost productivity by monitoring building occupancy. For example, a wireless occupancy sensor solution could instantly notify whether a meeting room is currently occupied or how many people on average use a particular room.
Occupancy detection also has a role to play in maintaining health and safety. For example, the technology makes it much easier to implement social distancing policies that will help keep an endemic variant of COVID-19 and other endemic diseases such as influenza at bay.
Read more: Wireless contact tracing highly relevant in a post-COVID-19 world
Wireless occupancy detection can also replace traditional lighting controls in a smart building or home. Improvements in efficiency from automated lighting can be dramatic. Such systems can significantly reduce energy use in commercial buildings, where lighting constitutes some 26 percent of total electricity consumption. According to data from the U.S. Department of Energy, installing occupancy-based sensor lighting controls can lead to energy savings of ten percent in an open-plan office, 45 percent in a warehouse, and as high as 60 percent in a restroom.
Employing occupancy sensors linked to HVAC controls can lead to similar energy savings. The sensors can adjust temperature settings, turn down airflows, or even turn the HVAC off depending on who's around.
Motion sensor types
Wireless occupancy sensors commonly use infrared (IR) light and microwaves, among other techniques, to detect the presence of people even when they're stationary.
The passive IR (PIR) sensor is the more common type due to its simplicity and relatively low cost. It is triggered by IR level change, like from a warm object such as a person. PIR sensors feature low energy consumption—the sensor's passive operation requires very little power compared to other motion detection systems—making a good alternative in an application where extended battery life is critical. Some downsides to PIR technology are that it struggles to detect tiny movements, must have direct line-of-sight with the moving object to operate, has limited range and restricted coverage area.
Microwave sensors address the weaknesses of PIR because they can cover wide areas, feature good range, and don't require line-of-sight with the moving object. The downsides are cost, and most significantly, power consumption. The units must constantly emit a microwave signal, which requires continuous power draw.
Hybrid or dual-technology sensors incorporating PIR and microwave in a single device combine the advantages of each technology for a high-performance motion detector system with a very low false detection rate. The downside is cost.
Read more: Improve battery life in Ultra Low Power wireless applications
Easy-fit occupancy detection
Brossard, Canada-based I-SYST, has developed the BLUEPYRO-M3225, a module providing plug-and-play motion/proximity detection capability, to support various wireless room occupancy detection applications. The product has been designed to help inexperienced PIR users quickly set up a wireless room occupancy detection system. It works in the home/building automation range, such as lighting control, security systems, smart thermostats, and in wildlife motion detection photography applications.
The I-SYST module integrates Nordic's nRF52832 SoC to deliver the processing power required for such applications. BLUEPYRO-M3225 features the Excelitas Technologies DigiPyro PYD2592, a dual-element PIR sensor with built-in signal processing, digital output, and wake-up/sleep mode functionality. The PIR sensor integration in the module enables a wireless solution with low electromagnetic interference (EMI) characteristics. The PIR sensor's wake-up feature is essential for battery-operated applications because it limits power use until a motion event is detected.
The wireless occupancy sensor market is on the move, with companies and individuals reaping the rewards of enhanced detection capability. For example, The Business Times reports that in Schneider Electric's offices in Kallang, Singapore, over a thousand sensors across nine floors track the occupancy of workstations and meeting rooms in near real-time. The data helps the company tailor lighting and HVAC according to attendance.
