These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

In personal vehicles, HVAC units are crucial for balancing energy efficiency with passenger comfort, especially as vehicle designs increasingly prioritize fuel efficiency, electrification, and emissions reduction. The performance of HVAC units directly impacts these objectives, making their optimization a priority in modern automotive engineering. Computational Fluid Dynamics (CFD) has emerged as an essential tool, enabling engineers to simulate, analyze, and refine the complex airflow and thermal dynamics within HVAC units. CFD empowers engineers to model intricate fluid and thermal behaviors within HVAC units, facilitating precise adjustments to critical components such as fans, ducts, and heat exchangers. By identifying and addressing inefficiencies during the design phase, CFD-based approaches reduce energy consumption and enhance HVAC unit reliability under diverse driving and environmental conditions. For electric and hybrid vehicles, where HVAC energy consumption significantly affects battery range, CFD optimizations are indispensable. Similarly, in conventional vehicles, improved HVAC efficiency reduces fuel consumption and emissions, supporting global sustainability goals. Beyond energy efficiency, CFD plays a pivotal role in enhancing passenger comfort. By simulating airflow distribution, velocity, and temperature gradients within the vehicle cabin, engineers can design HVAC units that ensure uniform, comfortable conditions for all occupants without excessive energy use. This capability is essential for maintaining occupant satisfaction across a broad spectrum of vehicle types and climatic conditions. CFD also facilitates the integration of advanced technologies, such as heat pumps and next-generation thermal management systems, which are increasingly utilized in electric and hybrid vehicles for efficient heating and cooling. Through virtual testing, CFD allows engineers to optimize these technologies, ensuring effective performance while minimizing energy demand. This paper presents case studies and practical applications of CFD in improving the efficiency, comfort, and adaptability of HVAC units across various personal vehicle types. It underscores the transformative impact of CFD in designing innovative, high-performance HVAC solutions that align with the demands of modern personal transportation.