Conference Agenda

Artificial Intelligence (AI) technologies, including machine learning, generative design, and neural networks, are transforming the design process by enabling rapid simulation of numerous scenarios and improving decision-making capabilities. This paper explores the application of advanced AI technologies in indoor environment design, focusing on the use of GPT-4o, a state-of-the-art natural language processing model. In this study, GPT-4o was utilized to design an air distribution system for an office, incorporating parameters such as geometrical information, heat sources, and design requirements. The model selected a suitable ventilation system and calculated essential design parameters, including airflow rate, supply air temperature, and diffuser placement. The design was validated using computational fluid dynamics (CFD) to ensure compliance with thermal comfort standards. Although GPT-4o demonstrated capabilities above those of a junior HVAC designer, it exhibited limitations in complex calculations and lacked memory retention. The study highlights the potential of AI in enhancing indoor environment design and suggests further improvements by iterative feedback. The findings underscore the transformative impact of AI in creating sustainable and efficient indoor spaces.

Accurate ventilation system sizing is critical to achieving energy efficiency while maintaining acceptable indoor air quality (IAQ) in commercial buildings. Traditional design approaches often assume full occupancy, leading to oversized systems with higher energy consumption. This study investigates the potential of using occupancy diversity factors to optimize ventilation system sizing, balancing energy efficiency with IAQ requirements. EnergyPlus simulations are conducted to model two scenarios for an office building: one assuming all the zones are fully occupied simultaneously and the other incorporating a diversity factor to represent typical occupancy patterns. The simulations produced different ventilation load patterns, allowing a comparison of energy use between the two scenarios. IAQ was assessed by monitoring carbon dioxide (CO2) levels under both scenarios to ensure that applying the diversity factor does not compromise IAQ. The findings indicate that average daily CO2 concentrations during occupied hours remain within acceptable limits even with reduced ventilation loads based on partial occupancy where occupants move between zones and not all zones are fully occupied at the same time. This approach demonstrated a potential 12.5% reduction in total air handling unit (AHU) energy consumption.

Decarbonizing both new and existing buildings rapidly is a multifaceted challenge. Given that people spend approximately 90% of their time indoors, the quality of the indoor environment profoundly impacts health and wellbeing. HVAC professionals are tasked with designing spaces that provide optimal conditions for their intended use while minimizing energy waste. Building ventilation systems are essential for maintaining indoor air quality and occupant health, with the choice of strategy impacting both energy consumption and indoor environmental quality (IEQ).

This paper presents a holistic comparison of three ventilation options, all meeting space conditioning requirements: Variable Air Volume (VAV) systems with terminal reheat, Dedicated Outdoor Air Systems (DOAS) with fan coil units, and DOAS with chilled beams. Using a whole life cycle perspective, these systems will be compared based on energy performance, IEQ impact, utility costs, upfront and lifecycle costs, and embodied and operational carbon emissions. Energy modeling of these options is conducted using IES VE software, with system performance metrics extracted from system and equipment data. The analysis aims to provide insights into the most effective ventilation strategies for achieving both energy efficiency and high IEQ in commercial buildings. By evaluating these systems comprehensively, the paper seeks to guide HVAC professionals in making informed decisions that balance environmental impact, cost, and occupant wellbeing.

This study investigates the dispersion of airborne pathogens emitted by a moving infectious individual in a hospital corridor, focusing on the impact of two distinct ventilation configurations on pathogen behavior. The corridor includes adjacent rooms with two ventilation setups: (1) air return vents near room entrances (Case A) and (2) air supply vents near room entrances (Case B). Pathogens were modeled using CO2 dispersion as an indicator, and simulations analyzed their movement across the corridor and into adjacent rooms.

The results demonstrate significant differences in pathogen dispersion between the two configurations. In Case A, the placement of return vents near room entrances effectively limited pathogen infiltration into rooms, maintaining a higher concentration within the corridor and enhancing pathogen removal via the ventilation system. In contrast, Case B, despite initial expectations of a barrier effect at the room entrances, allowed greater infiltration of pathogens. The downward airflow near the doors formed vortices, carrying pathogens into the rooms, where they spread extensively.

These findings reveal that ventilation design critically influences pathogen dispersion patterns. Case A proved more effective in containing pathogens within the corridor and accelerating their removal from the domain. The study underscores the importance of tailored ventilation strategies in mitigating airborne infection risks in healthcare environments.

Faced with the escalating global threats of natural disasters and environmental pollution, underground shelters are increasingly vital as safe havens. However, maintaining high indoor environmental quality (IEQ) within these enclosed spaces presents significant challenges. This paper introduces a novel, bio-inspired approach to enhance IEQ in underground shelters by developing zero-energy ventilation solutions. Mimicking the natural ventilation strategies employed by termite mounds and prairie dog burrows, we designed and computationally tested an integrated prototype ventilation system. This system synergistically combines thermal convection, inspired by termite mounds, and pressure differentials, inspired by prairie dog burrows, to optimize airflow and improve air quality. Utilizing Computational Fluid Dynamics (CFD) simulations, the integrated prototype demonstrated a superior ventilation performance, achieving a ventilation rate of up to 9.5 Air Changes per Hour (ACH). This wind and buoyancy-driven air circulation effectively enhanced air exchange, leading to a reduced Age of Air and This improved ventilation is anticipated to contribute to the removal of internally generated pollutants, such as CO₂. Furthermore, simulations indicated stable temperature regulation within a comfortable range of 18.5-28.5°C, achieved passively without reliance on mechanical ventilation or air conditioning. This innovative, zero-energy ventilation approach offers a sustainable and resilient solution for underground shelters, promising to create safer, healthier, and more sustainable environments for occupants during environmental, human-induced, and military crises and disasters.