In commercial buildings, Wi-Fi can double as a real-time occupancy sensor

Optimizing energy efficiency with Wi-Fi Location-Based Services
December 5, 2024

Energy management in commercial buildings still presents opportunities for innovation, especially when it comes to occupancy. We have studied a few methods to track occupancy levels in real-time, such as integrating lighting controls with HVAC systems. But what if we could use a piece of technology present in almost every building in the U.S.—something everyone uses all the time and barely thinks about (at least not after they know the password).

In a project for the U.S. Department of Energy, Slipstream worked with partners led by Center for Energy and Environment (CEE) to see if Wi-Fi technology could help with energy efficiency by capturing real-time occupancy data to guide building systems.

Location-based services (LBS) use cutting-edge real-time locating systems (RTLS) that harness wireless technology to pinpoint and follow the locations of people and objects. In this case, Wi-Fi LBS taps into access points (APs) to receive signals from Wi-Fi-enabled devices—such as smartphones, tablets, and laptops—that are always looking for available networks. By measuring the strength of these signals, we can accurately locate devices using a method called trilateration, employing multiple APs to enhance precision.

Project objectives

In this project, we sought to:

  • Create an open-source algorithm that determines building occupancy based on the locations of Wi-Fi-enabled devices.
  • Test and validate the algorithm to ensure the accuracy of occupancy data.
  • Develop and trial a communication protocol that shares occupancy data with open-source platforms like VOLTTRON for distributed sensing and control.
  • Showcase the algorithm in real-world commercial building environments.
  • Identify essential usability requirements for deploying cost-effective Wi-Fi RTLS in commercial operations.
  • Propose strategies and initiatives that encourage market acceptance and growth.

Project results

Using our algorithm, the Wi-Fi occupancy sensing approach was demonstrated and validated at commercial buildings located in Minnesota, Wisconsin, New York City, and Texas.

See the project page at the CEE website or read the full report at ResearchGate to learn more about how this project can lead to a simple, plug-and-play solution to smarter, more energy-efficient buildings.