Occupant-Centric Digital-Twin: An interactive real-time display, influencing human perception factor in thermal satisfaction decisions

Balancing optimal temperature setpoints with maintaining occupant comfort becomes increasingly challenging in open and shared workplaces without occupant control, such as co-working spaces or educational studios. Thermal comfort is influenced by various factors, including air temperature, humidity, air velocity, and individual preferences among diverse groups of occupants, such as age, gender, and clothing insulation. Despite advancements in understanding thermal comfort and developing technology to manage indoor environments, a gap remains in effectively involving occupants in the decision-making process.

A solution lies in better understanding variations in indoor climate and building occupants’ thermal preferences. This research explores how an Occupant-Centric Digital Twin (OCDT) display might address this by mapping indoor microclimates through a grid of IoT temperature sensors in real-time, data analysis, and interactive visualization to provide occupants with comprehensive insights into their indoor environment. By informing occupants about real-time temperature variations and live thermal feedback from co-occupants, the OCDT provides a platform for them to make informed decisions about their seating location based on thermal preferences.

To test the effectiveness of OCDT approach, occupant studies were conducted in a real-world shared workspace at the Carnegie Mellon University campus, where a large-screen display was used to present and visualize this data to occupants. Occupants could interact with the OCDT display to familiarize themselves in real-time with the temperature differentials within the space and their co-occupants’ thermal preferences.

The goal was to improve awareness and add agency for occupants to identify zones that meet their individual thermal preferences while working or inhabiting shared workspaces, which are typically managed by facility managers.

Results of the studies showed a significant effect of visualized live information through the OCDT display on participants’ decisions about how to occupy the space. On average, 57% of participants changed their seating choice after viewing the OCDT display. This percentage increased to 64% when the space was at half capacity and was even higher at lower capacities, due to more available spaces to move. Furthermore, exposure to the OCDT’s live environmental data and making seat selections accordingly significantly enhanced participants' thermal satisfaction. Using a scale of 1 to 5 to measure thermal satisfaction, the mean satisfaction increased by maximum 1.2, and minimum 0.4 for different capacities. This informed seat selection also resulted in occupants' preferred temperature adjustments aligning more closely with facility managers' setpoints, potentially leading to energy savings depending on the season.

Since this approach requires no intervention from facility managers, OCDT’s live visualization of occupant-centric data paves the way for a future where occupants of open workspaces can make informed decisions about where to sit and achieve their individual thermal comfort while in a shared environment.