The relationship between the indoor environment and the health of building occupants is complex. Local air quality, occupant’s activities, building construction, and HVAC design are just a few of the variables that make it difficult to provide optimal indoor air quality. This session will focus on strategic CO2 monitoring & sensor placement, ventilation rates, and air filter selections that lead to improved indoor air quality. ASHRAE Standard 241 will be referenced when presenting strategies for various programmatic space types. The importance of CO2 sensor placement in naturally ventilated classrooms will also be discussed.

A core concept of sustainable buildings is the balance of thermal comfort and optimal indoor air quality against energy consumption. Improved comfort and enhanced air quality typically demands increased energy consumption. This session will present how occupant-centric modeling can contribute to energy saving strategies; the session will also discuss how properly designed energy optimizing control systems can lead to energy saving predictive control strategies. Finally, the participants will learn how retro-commissioning and computational fluid dynamics can be leveraged to improved thermal comfort. Case studies will be reviewed to illustrate the findings through real-world examples.

This session showcases the transformative potential of digital twins and semantic data modeling in enhancing building performance, efficiency, and sustainability. The first presentation highlights the creation of an energy model digital twin for a 356,000 sq. ft. net-zero ready mixed-use building, integrating 8,000+ sensors and live BMS data to enable dynamic calibration, fault detection, and predictive analytics. The second presentation explores a tool that automatically generates semantic models from BIM data using standardized ontologies like ASHRAE Standard 223, streamlining the deployment of software applications such as automated fault detection and diagnostics. The third presentation details how ASHRAE’s Net-Zero Energy Global Headquarters utilized digital twin workflows and BIM data integration to optimize asset management, predictive maintenance, and energy performance. Together, these presentations demonstrate how digital twins and semantic models empower designers, operators, and owners to achieve intelligent, adaptive, and sustainable building management.