10 Ways To Calculate Building Occupancy
Key Takeaways:
Each method of people counting has its drawbacks.
The right sensor can provide information Nantum OS uses to drive savings.
Knowing how many people are in a building sounds simple but in commercial office buildings with dozens of floors and hundreds of workers, the scale presents a unique problem technology has stepped up to solve. Building occupancy technology has taken off during the pandemic, where maintaining low density is critical to health. As workers come back to the office, occupancy sensors will help occupiers and facility managers understand the new normal by tracking which spaces are being used and by how many.
Beyond the return to work, occupancy sensors save money by freeing up building operation teams and engineers, lowering heating and cooling when people aren’t there, and ultimately figuring out what unused space can be cut to save on rent. Because understanding building occupancy is so crucial, several types of technology have been developed to count. We break down the main types to give building owners and managers a better understanding of the options on the market.
Building Turnstiles
Turnstiles have become ubiquitous in buildings, airports, stadiums, and transit hubs because they’re simple and they work. Today turnstiles come in a variety of shapes and styles for every price point. Often turnstiles are also being used for security to manage access. Turnstiles are good at counting who comes in but struggle when it comes to counting who is leaving, making building occupancy counts estimates. As a relatively basic technology, some lower-end turnstile counters may not have much additional functionality or connectivity.
WiFi Device Scraping
Because smartphones are used so widely, counting WiFi connections is a great way to get a real-time count of occupancy. By default, smartphones are constantly sending WiFi probes, looking for a network. By simply adding up the number of WiFi probes on your network and controlling for various always-present devices, you can see how many people are within the building. WiFi occupancy sensors can cover a lot of ground, detecting all devices within 100 meters making them an attractive option at scale.
Security Cameras With Occupancy
Where security is paramount and cameras are already in place, a video-based occupancy counter may be a solution. Intelligent people counting software can analyze live video feeds to add up everyone currently on camera, removing them when they leave. Privacy isn’t a big concern because the process uses non-specific algorithms to determine if a shape on camera is a person, not what type of person or who they are. Relying on algorithms to make quick counts means accuracy isn’t always perfect.
Bluetooth Beacons
Some sensors are leveraging a new low-energy type of Bluetooth connection. Similar to WiFi counts, Bluetooth beacons track when a smartphone or tablet enters its proximity. Bluetooth beacons can also detect the proximity of devices to each other, and send information to the devices, making them a great tool for enforcing social distancing. Because the beacons are only 1-way transmitters, they protect privacy well.
Infrared Cameras
Infrared cameras are often known as optical turnstiles, operating without any obstacles for guests to pass through, using infrared to count patrons as they pass. Physical turnstiles can be prohibitive to disabled occupants, making cameras a more accommodating counting method. In high-rises with limited paths of entry and exit, infrared turnstiles can keep people moving by processing a high rate of people without slowing them with barriers or obstacles of more traditional turnstiles.
People Counting Sensors
Typically positioned above doors, people counting sensors keep count by quickly assessing actions and size of things that pass by with laster time of flight technology. Unlike other options, people counting sensors don’t need much light, making them precise and reliable in a variety of environments. People counting sensors make a good stand-alone solution if a building isn’t employing complementary technology.
Heartbeat Sensors
Heartbeat sensors are a recently developed technology that uses digital radar signal processing to determine unique micro vibrational patterns of heartbeats. Beyond its applications in healthcare, the technology is good at counting people. Because the process uses radar it doesn’t need light and can’t be fooled. Heartbeat sensors also promote health and safety by being able to detect when someone falls.
Temperature Sensors
Similar to infrared sensors, temperature sensors detect temperature distribution, able to determine minor changes in temperature when someone is present. Some use rough thermal imaging to detect movement, measuring flow. Temperature sensors have a somewhat limited range because of reliance on a field of view, the further from the sensor the less reliable the count.
Desk Occupancy
Relatively simply, desk occupancy sensors can be stuck on the underside of a desk or on a chair to determine if someone is using it. They use similar technology as other occupancy sensors but on a smaller scale, making them an affordable option for smaller counts. Because they only determine if a desk is occupied, they don’t have the added benefit of studying flow and traffic.
Energy Plug Load
Energy plug load sensors can estimate building occupancy based on average usage. With enough data on historic energy demand throughout the day, you can make an accurate estimate based on a building’s current power demand. When combined with a power strip that automatically shuts off when a space is unoccupied, serious savings are possible.
Understanding how spaces and rooms are used is one of the most important aspects of building management. Using occupancy sensors can provide valuable real-time data that enhances security, safety, and efficiency. It’s easy to see why occupancy sensors are needed. The hard part is figuring out which ones work best for your asset.
