Smart building

How to choose a people counting solution

With so many different types of people counting solutions on the market, it can be hard to know where to start. In this article, we run through the most important considerations when you choose a people counter for your application.
choose a people counting solution

Why implement a people counting solution?

Regardless of the technology used, all people counting solutions are essentially dedicated to the same task: counting and recording the number of people who occupy a given space at a given time.

While it may sound simple, the data provided by people counting solutions is surprisingly valuable and can be used in various ways to improve customer or employee experiences, optimize the use of space, and run businesses more efficiently.

Monitor traffic flow

People counting solutions are commonly used to monitor traffic flow in commercial premises open to the public. By keeping a running tally of room occupancy, people counters make it easy to spot overcrowding or underutilized spaces. Historical time-series data from people counting solutions can be easily used to predict trends in footfall at different times, whether throughout the day, the week, during holidays, or promotional events.

Improve staff allocation

People counting solutions enable managers to take actions that make life easier for customers and employees. For example, adjusting staff scheduling to cater to high footfall rates during peak times or changing layouts to ease congestion. Footfall data provides hard evidence to back up these decisions, rather than relying on inaccurate predictions.

Control energy expenditure

People counting solutions can control power-intensive HVAC, lighting and security systems directly responding to demand. Such “smart building” applications involve directly integrating people counting solutions into control systems capable of automatically providing ventilation, heat and/or light to areas where they are most needed. By automating these processes, people counters enable businesses to achieve immediate and dramatic reductions in energy expenditure and operating costs. (1,2)

choose a people counting solution

Optimize real-estate use

One of the most valuable applications of people counting solutions is the optimization of real- estate expenditure. Today, many employees spread their working time between home and the office – yet real estate prices remain high. The result is that many businesses are paying for space which they don’t actually need. (3)

People counting solutions provide immediate access to quantitative data on how space is used within the workplace. As well as enabling managers to identify poorly optimized spaces and improve the allocation of resources, people counting solutions provide the information required when considering downsizing to less expensive premises.

Types of people counting solutions

People counting solutions use a variety of sensor types to accomplish their goals. Choosing the best people counting solution for your application depends on several factors, including budget, required accuracy, and the level of privacy and anonymity needed.

2D and 3D stereovision cameras

Many people counting solutions rely on cameras to ”see” and identify people passing through their field of view. While some systems rely on ordinary cameras to capture 2D images, other “stereoscopic” people counting solutions feature dual cameras that enable them to see in 3D, improving their recognition accuracy effectively.

While cameras are generally a robust technique for people counting, camera hardware is typically more expensive than other people counting solutions. As well, processing images to automatically recognize people is a complex task which often means camera-based people counters require specialist calibration.

On top of this, many people are deterred from camera-based people counting solutions because they capture personally-identifying information. Even though this information is often anonymized or pseudonymized after capture, it’s simpler and more reliable to use an intrinsically anonymous system. (4)

WiFi and Bluetooth beacon

Beacon-based people counting solutions work by detecting WiFi- or Bluetooth-enabled devices (such as smartphones) within a particular area. While these people counting solutions are inexpensive to assess the number of people within an open space, they are inaccurate due to the built-in assumption that each person carries exactly one WiFi- or Bluetooth-enabled device on their person. (5)

Because individual devices can be distinguished from each other, these devices aren’t truly anonymous either, which means additional GDPR concerns for users.

Thermal cameras

While ordinary cameras capture visible light, thermal cameras detect light from the infrared part of the spectrum. This makes them capable of detecting temperature, enabling thermal-camera- based people counting solutions to detect people based on their body heat profile. While this provides the considerable advantage of anonymity, this type of people counting solution is typically the most expensive and often requires specialist installation and configuration.

Time-of-flight sensors

Time-of-Flight (ToF) people counting solutions use a similar operating principle to sonar. Emit a pulse (in this case, infrared light), measure the time taken for different parts of the pulse to reflect off the environment and return to a sensor, then use this information to collect depth information about the surroundings.

Terabee people counting solutions use infrared ToF technology to provide accurate people counting (95% and higher) at a fraction of the cost of other people counters. Moreover, because they capture only depth information with low spatial resolution, they are intrinsically anonymous by design.

choose a people counting solution
choose a people counting solution

Which people counting solution is best for you?

Most people counting solutions work by counting people as they pass through doorways in or out of a room. This means that your entrance setup is one of the most important considerations when choosing a people counting solution:

  • How wide is your entranceway? All people counting solutions have a limited field of view, which often depends on positioning. Any people counter must provide full coverage of an entrance/exit.
  • Is traffic monodirectional or bidirectional? Not all people counting solutions are well-suited to monitoring bidirectional traffic. However, monodirectional sensors may be easier and cheaper to implement if you have a one-way system.
  • Do people browse around the entrance? Simpler people counting solutions will count every person within their field of view. If people tend to browse around your entrance, this can produce inaccurate results – you’ll need to use a system capable of tracking individual people’s paths.

Who can benefit from a people counting solution?

Many different kinds of businesses and buildings can benefit from the installation of people counting solutions. People counting solutions are common in public-facing premises such as shops, malls, showrooms, restaurants, airports, and museums. However they can also be put to good use in private buildings such as offices, laboratories, and warehouses.

People counting solutions from Terabee

Terabee produces two people counting solutions: the People Counting L-XL and the People Counting M. Both use our unique infrared ToF technology to filter out static objects and detect people with high accuracy and complete anonymity – even in crowded areas with bidirectional traffic flow.

The People Counting L-XL is our flagship people counting solution. Roughly the same size as a fire alarm, the People Counting L-XL can be easily installed above almost any doorway, where it provides a wide field of view (1.50 x 1.10 m at a height of 2.40 m). For extra-wide entranceways up to 15 m across, multiple People Counting L-XL devices can be easily interconnected to provide full coverage.

The People Counting M is an ultra-compact and low-cost people counting solution developed for small entranceways. Weighing in at just 85 g, the People Counting M makes people counting viable for applications where higher-cost devices make it prohibitive. To find out more about our world-leading people counting solutions, get in touch with Terabee today.

choose a people counting solution

References and further reading

  1. King, J. Smart Buildings: Using Smart Technology to Save Energy in Existing Buildings. SMART BUILDINGS 55.
  2. Weng, T. & Agarwal, Y. From Buildings to Smart Buildings—Sensing and Actuation to Improve Energy Efficiency. IEEE Des. Test. Comput. 29, 36–44 (2012).
  3. Occupancy monitoring: what it is & why it’s essential. Terabee (2022).
  4. Ahmad, J., Larijani, H., Emmanuel, R., Mannion, M. & Javed, A. Occupancy detection in non-residential buildings – A survey and novel privacy preserved occupancy monitoring solution. Applied Computing and Informatics (2018) doi:10.1016/j.aci.2018.12.001.
  5. Yang, Y., Cao, J., Liu, X. & Liu, X. Wi-Count: Passing People Counting with COTS WiFi Devices. in 2018 27th International Conference on Computer Communication and Networks (ICCCN) 1–9 (2018). doi:10.1109/ICCCN.2018.8487420.

Related products

My Cart