Reliability analysis of heating ventilation and air-conditioning (HVAC) system of passenger cars using field failure data

• Geographical disparity in HVAC failures analyzed using field data across India. • Pareto analysis and probability modeling identify key high-failure zones. • Extreme climates and pollution linked to frequent refrigerant and blower issues. This study presents a comprehensive reliability analysis of Heating, Ventilation, and Air Conditioning (HVAC) systems in passenger cars, utilizing large-scale field failure data segmented by region, zone, and area across India. A methodology is proposed that identifies outliers from the field failure data and employs Pareto analysis, statistical modeling, and reliability analysis to identify high-risk segments and inform targeted design and maintenance interventions, as well as design improvements. The Pareto and reliability study shows that approximately 80% of HVAC failures are concentrated in just a few regions, namely Delhi, Uttar Pradesh, Maharashtra, and Gujarat, which contribute the highest number of failure incidents. The subsystems/ components, such as blower assemblies and refrigerant lines, are the primary contributors to system failures. The study established the Weibull 2/3 parameter model as the best fit for failure prediction across most geographies. These findings underscore the crucial need for region-specific maintenance strategies and targeted design enhancements, such as improved motor bearings and enhanced sealing, to minimize downtime and prolong HVAC lifespan in high-failure areas. The study demonstrates the value of using real-world operational data to inform predictive maintenance and optimise HVAC reliability across geographically diverse conditions.