TESTING METHODS FOR PASSENGER CAR HEATING SYSTEMS

Аннотация

The performance of heating systems in passenger cars is a crucial factor affecting thermal comfort, safety, and energy efficiency, particularly in cold climates. Despite advances in automotive HVAC (Heating, Ventilation, and Air Conditioning) systems, comprehensive testing methods for heating functionality remain a challenge due to vehicle design diversity, user expectations, and environmental factors. This study investigates and evaluates various testing methods for heating systems in light vehicles based on international standards and practical approaches. Using experimental and simulation techniques, several heating configurations are analyzed for heat-up time, temperature distribution, energy consumption, and occupant comfort. Results suggest that multi-zone thermal mapping and standardized driving cycles provide the most reliable assessment framework. Furthermore, the study proposes improvements to current testingprotocols to ensure better reproducibilityand alignment with real-world conditions. Keywords: passenger cars, heating system, HVAC, thermal comfort, vehicle testing, energy efficiency. 1.Introduction 1.1Background Passenger cars operating in cold climates require efficient and reliable heating systems to ensure occupant comfort, maintain driver alertness, and prevent windshield fogging or icing. Traditional internal combustion engine (ICE) vehicles utilize waste heat from the engine for cabin heating, whereas modern hybrid and electric vehicles (EVs) rely on electric heaters, heat pumps, or phase change materials. As the automotive industry transitions towards electrification, the importance of precise and standardized heating performance assessments becomes more critical due to limited onboard energy sources. 1.2Importance ofHeating System Testing Inadequate heating system performance can lead to discomfort, increased defrosting times, poor visibility, and even health hazards. Consequently, both regulatory authorities and automotive manufacturers prioritize the development of reliable testing methods. However, variations in vehicle architecture, sensor calibration, occupant behavior, and climatic conditions make standardized testinga complex task. 1.3Research Objectives This study aims to identify, evaluate, and recommend appropriate testing methods for light vehicleheating systems. Specific objectives include: Reviewing current heating system technologies and configurations Analyzing international testing standards and procedures Designing and implementing experimental and simulation-based evaluations Proposingimprovements to testing methodologies based onresults 2.Literature Review 2.1Overview ofAutomotiveHeating Systems Heating systems in passenger cars vary depending on the vehicle's propulsion system. In ICE vehicles, coolant-based heat exchangers transfer engine heat to the cabin via air ducts. EVs, https://ijmri.de/index.php/jmsi volume 4,issue5,2025 565 lacking a high-temperature waste heat source, employ PTC (Positive Temperature Coefficient) heaters, resistive elements, or more advanced heat pumps. Recent innovations include waste heat recovery systems, infrared panels, and thermoelectric devices [1]. 2.2International Testing Standards Organizations such as the Society of Automotive Engineers (SAE), International Organization for Standardization (ISO), and European Committee for Standardization (CEN) have developed specific guidelines toevaluate vehicle HVAC performance. Key documents include: SAEJ2234: Performance ofVehicle ClimateControlSystems [2] ISO 14505-2: Evaluation ofthermal comfort using humansubjects [3] ECERegulation No.122: Uniform provisions concerning heating systems in vehicles [4] 2.3Thermal Comfort and Energy Efficiency Thermal comfort is a subjective and complex metric influenced by air temperature, humidity, air velocity, radiation, clothing, and metabolic rate. The Fanger PMV (Predicted Mean Vote) index and ISO 7730 standard offer frameworks for evaluating comfort levels [5]. In electric vehicles, optimizing heating efficiency is crucial due to the direct impact on driving range. Therefore, testingmust balance comfort withenergy consumption. 2.4TestingChallenges and Gaps Existing testing methods often fail to capture transient effects, real-world driving conditions, or multi-zone variability within the vehicle cabin. Moreover, conventional sensor placement may not accurately represent human perception. These limitations necessitate improved procedures incorporating thermal mannequins, infrared thermography, and advanced computational fluid dynamics (CFD) models [6][7]. 3.Methodology 3.1Research Design The research utilizes a mixed-method approach combining experimental tests and numerical simulations. The study was conducted on two types of passenger vehicles: a gasoline-powered compact sedan and an all-electric crossover. Tests were performed in a controlled climatic chamber at ambient temperatures ranging from -20°Cto +5°C. Fig1. Test machine car heating syste