Browse Topic: Air conditioning

Items (1,361)

Simulation-Based Investigation and its Experimental Validation of the Thermal Behaviour of a Battery Electric City Bus

2025-01-0266To be published on 07/02/2025

Electrification of city busses is an important factor for decarbonisation of the public transport sector. Due to its strictly scheduled routes and regular idle times, the public transport sector is an ideal use case for battery electric vehicles (BEV). In this context, the thermal management has a high potential to decrease the energy demand or to increase the vehicles range. The thermal management of an electric city bus controls the thermal behaviour of the components of the powertrain, such as motor and inverters, as well as the conditioning of the battery system and the heating, ventilation, and air conditioning (HVAC) of the drivers’ front box and the passenger room. The focus of the research is the modelling of the thermal behaviour of the important components of an electric city bus in MATLAB/Simscape including real-world driving cycles and the thermal management. The heating of the components, geometry and behaviour of the cooling circuits as well as the different mechanisms of

Schäfer, Henrik, Meywerk, Martin, Hellberg, Tobias

Tonal noise investigation of automotive HVAC systems : a hybrid method

2025-01-0027To be published on 05/05/2025

There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of

Bennouna, Saad, Alaoui, Mohamed, Henner, Manuel

Air Conditioning Service Procedures for Off-Road Work Machines and Agricultural Tractors Using HFC-134a or HFO-1234yf Refrigerant

J3126_202504 (Historical)

04/14/2025

This SAE Recommended Practice is intended to provide technicians with safe and efficient techniques and general equipment recommendations for servicing mobile air conditioning systems in off-road, self-propelled work machines as defined in SAE J1116 and tractors and machinery for agriculture and forestry as defined in ASABE standard ANSI/ASAE S390. Both refrigerants HFC-134a (R-134a) and HFO-1234yf (R-1234yf) are covered. Many service procedures are similar for both refrigerants, but recovery, recycling, charging, and electronic leak detection tools can be unique to each refrigerant.

HFTC6, Operator Accommodation

Investigation of the Blockage Phenomenon in Closed Wall Wind Tunnels During the Testing of Bluff Automotive Bodies with Large Wakes in Yawed Configurations

2025-01-8786

04/01/2025

The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been very difficult to experimentally analyze the effects that are occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier works by the author and similarly to those studies uses the computational fluid dynamics analysis of three bodies that generate large wakes to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, and forces experienced by the vehicle model when it is in yawed conditions up to 20 degrees. This is accomplished by executing a series of CFD configurations with varying sized cross sections from 0.4% to 14% blockage enabling an approximation of free air conditions as a reference

Gleason, Mark, Riegel, Eugen

Automatic Generation of HVAC Ducting System Designs Using Topology and Shape Optimization

2025-01-8656

04/01/2025

In this paper, the topology and shape optimization of a vehicle Heating, Ventilation, and Air Conditioning (HVAC) system is presented. The CFD and optimization methodologies are implemented within AcuSolve™ software. The topology optimization algorithm computes the geometry, where the design domain is parameterized with a field of porosity design variables which indicates the material, fluid or solid, throughout the domain. The optimization is performed using the continuous adjoint approach by the Galerkin Least Squares solver on which the AcuSolve™ solver is based. The design is further improved by using shape optimization. To optimize the geometrical shape, a combination of smooth perturbations, in terms of so called morph shapes, are used to deform the geometrical shape in the optimization algorithm. To this end, a parameterization of the design space is done using a moderate number of design variables, each associated with a morph shape. The two optimization phases are connected by

Papadimitriou, Dimitrios, Sandboge, Robert

Battery Thermal Management System for PHEV by using Air Conditioning Heater System

2025-01-8172

04/01/2025

Toyota Motor Corporation pursuing an omnidirectional strategy that includes battery electric vehicle (BEV), plug-in hybrid electric vehicle (PHEV), and fuel cell electric vehicle (FCEV) to accelerate electrification. One of the technical challenges with our xEV batteries which feature good degradation resistance and long battery life, is that regenerative braking cannot be fully effective due to the decrease in regenerative power in some situations, such as low battery temperature. For the electrified vehicles with an internal combustion engine such as PHEVs, the solution has been running the engine to increase deceleration through engine braking during coasting. PHEVs are expected to extend their cruising range and enhance EV driving experience as "Practical BEVs". While increasing battery capacity and enhancing convenience, the restrictions on EV driving opportunity due to low battery temperature may negatively affect PHEV’s appealing. As an alternative, introducing a battery heater

Hoshino, Yu

Power Loss Estimation in Poly-V Belts for Micro and Mild Hybrid Powertrains Using the Generalized Maxwell Model

2025-01-8316

04/01/2025

In modern automotive powertrains, the front-end accessory drive represents a crucial subsystem that guarantees the proper functioning of micro and mild hybrid configurations and auxiliary vehicle functionalities. The motor/generator (12 V or 48 V), the air conditioning compressor and other accessories rely on this subsystem. Therein, the poly-V belt is the main transmission mechanism. From an efficiency standpoint, its behavior is usually represented through slip and elastic shear phenomena. However, the viscoelastic nature of the compounds that constitute the belt layers demand a more detailed approximation of the loss mechanisms. The quantification of such losses allows evaluating the performance of the e-machine integrated in the powertrain. This work models the belt through a lumped-parameter time-domain model, where domains are discretized into multiple elements and represented through the generalized Maxwell model. Loss contributions due to bending, stretching, compression and

Galluzzi, Renato, Amati, Nicola, Bonfitto, Angelo, Hegde, Shailesh, Zenerino, Enrico, Pennazza, Mario, Staniscia, Emiliano

Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery

2025-01-8154

04/01/2025

A specific thick film heater (TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is estab-lished. The heat transfer and fluid performance of the TFH is analyzed using a computational fluid dynamics soft-ware. The performance of TFH is measured on a test bench, and the measured data is used to validate the developed model. Using the established model, the heating efficiency of TFH is studied for different inlet temperatures and flow rates, and the influence of the fin spoiler structure on TFH heating efficiency and the heating board temperature is investigated. The result indicates that the spoiler structure has a large effect on the board heating temperature, but has little effect on the heating efficiency. An orthogonal experimental design method is used to optimize the design of the fins and water channels, and the purpose is to reduce the board heating temperature for preventing over burning. Under the 25°C inlet

Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin

Development of Ceramic Humidity Regulator (CHR) Using Honeycomb Type PTC Heater to Improve Electric Vehicle Driving Range in Winter

2025-01-8177

04/01/2025

With Rapid growth of Electric Vehicles (EVs) in the market challenges such as driving range, charging infrastructure, and reducing charging time needs to be addressed. Unlike traditional Internal combustion vehicles, EVs have limited heating sources and primarily uses electricity from the running battery, which reduces driving range. Additionally, during winter operation, it is necessary to prevent window fogging to ensure better visibility, which requires introducing cold outside air into the cabin. This significantly increases the energy consumption for heating and the driving range can be reduced to half of the normal range. This study introduces the Ceramic Humidity Regulator (CHR), a compact and energy-efficient device developed to address driving range improvement. The CHR uses a desiccant system to dehumidify the cabin, which can prevent window fogging without introducing cold outside air, thereby reducing heating energy consumption. A desiccant system typically consists of two

Hamada, Takafumi, Shinoda, Narimasa, Konno, Yoshiki, Ihara, Yukio, Ito, Masaki

Control Trajectory Optimization of Electric Vehicle Heat Pump-Based Cabin Heating System

2025-01-8144

04/01/2025

Optimal control of battery electric vehicle thermal management systems is essential for maximizi ng the driving range in extreme weather conditions. Vehicles equipped with advanced heating, ventilation and air-conditioning (HVAC) systems based on heat pumps with secondary coolant loops are more challenging to control due to actuator redundancy and increased thermal inertia. This paper presents the dynamic programming (DP)-based offline control trajectory optimization of heat pump-based HVAC aimed at maximizing thermal comfort and energy efficiency. Besides deriving benchmark results, the goal of trajectory optimization is to gain insights for practical hierarchical control strategy modifications to further improve real-time controllers’ performance. DP optimizes cabin inlet air temperature and flow rate to set the trade-off between thermal comfort and energy efficiency while considering the nonlinear dynamics and operating limits of HVAC system in addition to typically considered cabin

Cvok, Ivan, Deur, Josko

Emissions Savings from Efficient Mobile Air-Conditioning (MAC) Systems in Passenger Vehicles

2025-01-8156

04/01/2025

Mobile Air-Conditioning (MAC) systems are a substantial source of energy consumption and CO₂ emissions in passenger vehicles, particularly for electrified vehicles under real-world operating conditions. Enhancing the efficiency of such systems is imperative to achieving greater energy efficiency and maintaining occupants’ comfort. In recognition of their significance, MAC systems can be classified as eco-innovative technologies under EU Regulation 2019/631, effective from 2025. This study lays the groundwork for a methodology to calculate CO₂ savings from eco-innovative MAC systems in passenger cars. The approach compares CO₂ emissions between baseline and eco-innovative vehicles under active and inactive MAC systems. Literature-derived indicative ambient conditions are applied to reflect realistic MAC usage scenarios in Europe. The testing protocol follows the WLTP procedure under controlled ambient conditions, including temperature, humidity, and solar irradiation, which can either

Di Pierro, Giuseppe, Currò, Davide, Gil-Sayas, Susana, Fontaras, Georgios

Modeling and Control Strategies of the Thermal Management System for Electric Vehicles

2025-01-8190

04/01/2025

The electric vehicle thermal management system is a critical sub-systems of electric vehicles, and has a substantial impact on the driving range. The objective of this paper is to optimize the performance of the heat pump air conditioning system, battery, and motor thermal management system by adopting an integrated design. This approach is expected to effectively improve the COP (Coefficient of Performance) of cabin heating. An integrated thermal management system model of the heat pump air conditioning system, battery, and motor thermal management system is established using AMEsim. Key parameters, such as refrigerant temperature, pressure, and flow rate at the outlet of each component of the system are compared with the measured data to verify the correctness of the model established in this paper. Using the established model, the impact of compressor speed on the heating comfort of the cabin under high-temperature conditions in summer was studied, and a control strategy for rapid

Zhang, Min, Li, Liping, Zhou, Jianhua, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin

Test Procedure for Determining Refrigerant Emissions from Mobile Air Conditioning Systems

J2763_202503 (Current)

03/25/2025

This SAE Standard covers the mini-shed testing methodology to measure the rate of refrigerant loss from an automotive air conditioning (A/C) system. This SAE procedure encompasses both front and rear air conditioning systems utilizing refrigerants operating under sub-critical conditions. The SAE procedure will cover multiple refrigerants to emission testing and is utilized for evaluating air condtioning systems. Heat pump systems can also be evaluated; however, they will have different usage and mission profiles.

Interior Climate Control MAC Supplier Committee

SAE Aerospace Applied Thermodynamics Manual Aerothermodynamic Systems Engineering and Design

AIR1168/3B (Current)03/25/2025

This section presents methods and examples of computing the steady-state heating and cooling loads of aircraft compartments. In a steady-state process the flows of heat throughout the system are stabilized and thus do not change with time. In an aircraft compartment, several elements compose the steady-state air conditioning load. Transfer of heat occurs between these sources and sinks by the combined processes of convection, radiation, and conduction in the following manner: 1 Convection between the boundary layer and the outer airplane skin. 2 Radiation between the external skin and the external environment. 3 Solar radiation through transparent areas directly on flight personnel and equipment and on the cabin interior surfaces. 4 Conduction through the cabin walls and structural members. 5 Convection between the interior cabin surface and the cabin air. 6 Convection between cabin air and flight personnel or equipment. 7 Convection and radiation from internal sources of heat such as

AC-9 Aircraft Environmental Systems Committee

R-1234yf Service Hose, Fittings, and Couplers for Mobile Refrigerant Systems Service Equipment

J2888_202502 (Current)

02/25/2025

This SAE Standard covers fittings, couplers, and hoses intended for connecting service hoses from mobile air-conditioning systems to service equipment such as charging, recovery, and recycling equipment (see Figure 1). This specification covers service hose fittings and couplers for MAC service equipment service hoses, per SAE J2843 and SAE J2851, from mobile air-conditioning systems to service equipment such as manifold gauges, vacuum pumps, and air-conditioning charging, recovery, and recycling equipment.

Interior Climate Control Service Committee

Research on Thermal Management System of New Energy Vehicles Based on Heat Pump Air Conditioner

2025-01-7005

01/31/2025

With the popularity of electric vehicles, the application development of heat pump type automobile air conditioning system has been focused. Meanwhile, the traditional R134a needs to be replaced by more environmentally-friendly refrigerants under the Kigali Amendment. In this paper, a novel direct expansion heat pump air conditioning system with three circuit switching (DXACS) was proposed, and three low GWP refrigerants R1234yf, R1234ze(E) and R290 were carried out to evaluate the system performance. The results show that the winter range attenuation ratio of DXACS is 26.9%, significantly lower than the prototype EV360 (57.5%); the DXACS with R290 shows the best heating performance, COPh and qcv are 2.3% and 57.3% higher than R134a in extremely cold conditions, respectively. This study provides valuable insights for the development of efficient and green thermal management technology of new energy vehicles.

Zhu, Tengfei, Liu, Ye, Chen, Qinghua

Thermal Management of Electric Heavy-Duty Truck Equipped with Water Source Heat Pump in Winter Condition

2025-01-7010

01/31/2025

The electric heavy-duty truck has been receiving much attention due to its low carbon emission characteristic. This paper presents the winterized design of thermal management for an electric heavy-duty truck. The changes of important parameters in the modes of rapid heating from a cold start battery, cabin defrosting, and cabin heating in winter are discussed based on water source heat pumps. It takes 1300 seconds to warm the battery to 5°C from an ambient temperature of -10°C. Under the same heat production condition, the proposed water source heat pump can save 28.2% energy comparing with the air source heat pump, the cabin air conditioner air outlet can stay above 40°C for more than 5 minutes, and the cabin temperature can be stabilized at 20°C to meet the heating demand of the crew in winter.

Yu, Bo, Dai, Huwei, Lin, Jiewei, Han, Feng, Jiang, Feifan, Zhang, Junhong

R-1234yf [HFO-1234yf] Refrigerant Electronic Leak Detectors, Minimum Performance Criteria

J2913_202501 (Current)

01/21/2025

This SAE Standard provides testing and functional requirements to meet specified minimum performance criteria for electronic probe-type leak detectors. The equipment specified here will identify smaller refrigerant leaks when servicing motor vehicle air conditioning systems, including those engineered with improved sealing and smaller refrigerant charges to address environmental concerns and increase system efficiency. This document does not address any safety issues concerning the equipment design or use beyond that of sampling a flammable refrigerant, save those described in 3.1 and 3.2 of this document. All requirements of this standard shall be verified in SAE J2911.

Interior Climate Control Service Committee

Experimental Investigation of Spray Characteristics Direct Injected in Atmospheric Ambient Conditions by a Multi-Hole Injector

2024-36-0156

12/20/2024

The aim of the present work was to characterize macroscopic spray parameters of a multi-hole direct injection injector for spark ignition engine applications. The geometry, the position of spray boundaries the overall cone angle, the spray vertical penetration and the vertical spray length were evaluated by processing the spray images recorded at 3300 frames per second. The frequency of recording images was suitable for capturing all the spray developments in all tested conditions. The tested fluid was EXXSOL D60 for simulating ethanol spray characteristics due to its similar properties and due to security reasons. The injector was tested outside the engine and into an open acrylic chamber being injected into atmospheric air conditions of the laboratory. The injection pressure was set up in 100 bar and the simulated engine speed were set up in MOTEC ECU in 3000 rpm, 3600 rpm and 4000 rpm. The injection durations were set up in 3,0 ms for 3000 rpm and 2.3 ms for 3600 rpm and 4000 rpm

Guzzo, Márcio Expedito, Fonseca, Lucas Guimarães, Duarte, Thales Henrique Ramos, Baeta, José Guilherme Coelho, Huebner, Rudolf, Pujatti, Fabrício José Pacheco

Rating Air-Conditioner Evaporator Air Delivery and Cooling Capacities

J1487_202412 (Current)

12/06/2024

The purpose of this SAE Recommended Practice is to establish uniform test procedures for measuring and rating air delivery and cooling capacity of truck and off-road self-propelled work machines used in earth moving, agriculture, and forestry air-conditioner evaporator assemblies. It is the intent to measure only the actual cooling capacity of the evaporator. It is not the intent of this document to rate and compare the performance of the total vehicle air-conditioning system.

Truck and Bus Windshield Wipers and Climate Control Comm

A Predictive Controller for Battery Cooling and Air-Conditioning Systems to Tackle the Comfort-Safety-Efficiency Dilemma

2024-28-0147

12/05/2024

The advent of electric vehicles has increased the complexity of air conditioning systems in vehicles which now must maintain the safety and comfort of occupants while ensuring that the high voltage battery temperature is kept within safe limits. This new task is critical due to the influence of the cell and battery pack temperature on the efficiency. Moreover, high temperatures within the battery pack can lead to undesirable effects such as degradation and thermal runaway. Classical solutions to this problem include larger air conditioning components to support worst case scenario conditions where the cooling request from the battery and the cabin happen at the same time. In such conditions, for the safety of the battery, the cooling request is assigned to battery system which may cause discomfort to the passengers due the significant temperature increase in the cabin during such events. The probability of such events happening is certainly dependent on the weather conditions but in

Palacio Torralba, Javier, Kulkarni, Shridhar Diliprao, Shah, Geet, Jaybhay, Sambhaji, Kapoor, Sangeet, Locks, Olaf

Leak Detection: Stability and Compatibility Criteria of Fluorescent Refrigerant Leak Detection Dyes for Mobile Air-Conditioning Systems

J2297_202412 (Current)

12/05/2024

This SAE Standard applies to dyes intended to be introduced into a mobile air-conditioning system refrigerant circuit for the purpose of allowing the application of ultraviolet leak detection. In order to label any product(s), they shall meet SAE J2297, the certification process as described in SAE J2911 must be followed, and the documentation described in Appendix A shall be submitted to SAE.

Interior Climate Control Fluids Committee

A Design Synthesis Approach to Improve HVAC Acoustic Performance of Passenger Vehicles

2024-28-0221

12/05/2024

Noise induced by the Heating, Ventilation and Air conditioning (HVAC) system inside a vehicle cabin can cause significant discomfort to passengers and, in turn, affect the brand image in a competitive automotive market. HVAC acoustic performance has become more prominent with the ongoing transformation from Internal Combustion (IC) to Electric Vehicle (EV) segments. For this reason, acoustic quality is increasingly prioritized as a key design issue throughout the entire development process of the HVAC system. This paper covers the design synthesis considering air handling unit-induced airborne and structure-borne noise of a dashboard-mounted HVAC system to achieve better NVH refinement inside vehicle while maintaining thermal performance. This study began by analysing HVAC-induced blower motor, impeller, air ducts, vents, and recirculation suction noise from the vehicle level to subsystem level and eventually at the component level. At the subsystem level, major noise source

Titave, Uttam Vasant, Naidu, Sudhakara, Kalsule, Shrikant

Design Optimization of Air Duct for Noise Reduction Using Gaussian Process Regression Algorithm

2024-28-0042

10/17/2024

In the context of Battery Electric Vehicles (BEVs), airborne noise from Heating, Ventilation and Air Conditioning (HVAC) ducts becomes a prominent concern in the view of passenger comfort. The automotive industry traditionally leverages Computational Fluid Dynamic (CFD) simulation to refine HVAC duct design and physical testing to validate acoustic performance. Optimization of the duct geometry using CFD simulation is a time-consuming process as various design configurations of the duct have to be studied for best acoustic performance. To address this issue effectively, the proposed a novel methodology uses Gaussian Process Regression (GPR) to minimize duct noise. Present solution demonstrates the power of machine learning (ML) algorithms in selecting the optimal duct configuration to minimize noise. Utilizing both real test data and CFD results, GPR achieves remarkable accuracy in design validation, especially for HVAC air ducts. The adoption of GPR-based ML algorithms significantly

Althi, Tirupathi Rao, Manuel, Naveen, K, Manu

Air Conditioning Systems for Subsonic Airplanes

ARP85G (Current)

10/03/2024

This SAE Aerospace Recommended Practice (ARP) contains guidelines and recommendations for subsonic airplane air conditioning systems and components, including requirements, design philosophy, testing, and ambient conditions. The airplane air conditioning system comprises that arrangement of equipment, controls, and indicators that supply and distribute air to the occupied compartments for ventilation, pressurization, and temperature and moisture control. The principal features of the system are: a A supply of outside air with independent control valve(s). b A means for heating. c A means for cooling (air or vapor cycle units and heat exchangers). d A means for removing excess moisture from the air supply. e A ventilation subsystem. f A temperature control subsystem. g A pressure control subsystem. Other system components for treating cabin air, such as filtration and humidification, are included, as are the ancillary functions of equipment cooling and cargo compartment conditioning

AC-9 Aircraft Environmental Systems Committee

Control of Water Carryover from the Environmental Control System and Condensation on the Structure

AIR1204A (Current)

10/03/2024

This Aerospace Information Report (AIR) outlines the design considerations and criteria for the control of water carryover from the environmental control system (ECS) with respect to causes and indicated corrective or preventative action. In addition, condensation on structure will be reviewed with possible preventative action described.

AC-9 Aircraft Environmental Systems Committee

Environmental Control Systems Terminology

ARP147E (Current)

10/03/2024

This ARP provides the definition of terms commonly used in aircraft environmental control system (ECS) design and analysis. Many of the terms may be used as guidelines for establishing standard ECS nomenclature. Some general thermodynamic terms are included that are frequently used in ECS analysis, but this document is not meant to be an inclusive list of such terms.

AC-9 Aircraft Environmental Systems Committee

A Study on Cabin Heat Load Reduction Using Solar Reflective Glasses in Automotive Application

2024-28-0101

09/19/2024

Over the past few decades, there has been a notable increase in stakeholder’s attention on Earth's climate. The automotive industry, being a major contributor to this phenomenon, has been endeavoring to mitigate its impact through various measures. These efforts include reducing emissions in existing internal combustion engine (ICE) vehicles and promoting electric vehicles (EVs) as a feasible alternative for consumers. Despite these initiatives, there remains a persistent challenge in improving the fuel economy and driving range of vehicles. India, located along the Tropic of Cancer, experiences both tropical and subtropical climates. As a result, a substantial portion of the total heat absorbed is from solar radiation. The higher heat load necessitates extensive use of air conditioning (AC) systems, which significantly contributes to the overall power consumption of vehicles. Various measures are being implemented to mitigate this heat load and enhance the efficiency of AC operations

Kumar, Sunny, Venu, Santosh, Raj, Shivam, Kandekar, Ambadas

Design and Development of a Green Mobile Air Conditioning System for Electric Vehicles

2024-28-0108

09/19/2024

Electric Vehicles (EVs) have rapidly grown as a means for clean mobility, as they zero down tail pipe emission of greenhouse gases. Additionally, greenhouse gases such as Hydro-Fluoro-Carbon (HFCs) based refrigerants used in Mobile Air-Conditioning (MAC) are under global scrutiny for their high Global Warming Potential (GWP). To prevent earth environment to pass the climate tipping point that will be irreversible within human capacity, actions such as rapid phase down of high GWP rated HFCs under Kigali Amendment to Montreal Protocol are enacted. India being amongst signatory nations is now working to fast track phase-down use of high GWP refrigerant and transit to low GWP refrigerant options. Nearly half of national HFCs use and emissions are for manufacture and service MAC. Vehicle OEMs supplying to markets in developing countries (e.g. European nation and non-Article 5 Parties) have already phased out HFC-134a (GWP=1400) through alternate refrigerant solutions. The work presented

Maurya, Anurag, Venu, Santosh, Kapoor, Sangeet, Khan, Farhan

Smart Efficient ECO AC for Small Commercial Electric Vehicle

2024-28-0087

09/19/2024

The proposed smart, efficient eco-cooling strategy leverages the AC system's efficiency sensitivity to the vehicle speed and the thermal storage of the cabin to coordinate the AC operation with the vehicle speed profile by actively shifting the AC thermal load toward the more efficient region at higher vehicle speeds. An investigation is now being conducted on vehicle cabin climate control systems to lower energy consumption and enhance battery electric vehicle range when in pure electric mode. OEMs of electric vehicles are always searching for novel concepts that will extend the driving range of their vehicles. Basically, an air conditioning system needs high-voltage power from high-voltage battery packs to keep the interior of the cabin in a comfortable temperature range during the summer. In order to meet these demands, the AC system in electric vehicles becomes an additional power consumer. This smart ECO AC system consists of the importance and impact of the various components of

Agalawe, KIRAN R., Nagarhalli, Prasanna V, HAJGUDE, NIKHIL

Evaluations to Identify the Necessity of Thermal Protector in Automotive Air Conditioning Compressor (Vane Type) in a Hot Climate Country

2024-28-0109

09/19/2024

In automotive air conditioning systems, compressor is used to convert low pressure low temperature refrigerant into high pressure high temperature refrigerant. Various types of compressors like swash plate, rotary vane, scroll etc. are widely used in the automotive industry for air conditioning applications. In rotary vane compressors, thermal protector is used as a safety device, designed to prevent the compressor from overheating during refrigerant compression process. When the discharge temperature exceeds the preset limit of thermal protector, the thermal protector will activate and stop the electrical supply to compressor clutch to stop the compressor operation thereby preventing potential damage to air conditioning system, engine, and other nearby parts of the vehicle. This technical paper explores the various real-world scenarios for a hot country like India, which may result into higher discharge temperatures of compressor resulting into activation of thermal protector. The

Mittal, Sachin, Saha, Aniket, Kumar, Mukesh, Umbarkar, Shriganesh

1D and 3D Coupled Thermal Simulation of HVAC at Defrost Mode Using Dual Stream Heat Exchanger Model

2024-28-0067

09/19/2024

In today's fast-paced lifestyle, people spend a maximum amount of time for traveling, leading to a heightened demand for thermal comfort. Automotive HVAC play a crucial role in providing conditioned air to ensure comfort while traveling. Evaluating HVAC systems performance including delivery systems, heat exchanger efficiency, air thermal mixing zones, and temperature distribution are essential to maintain fuel economy and modern vehicle styling. However, accurately predicting cooling/heating performance using CFD simulations poses challenges due to the complex nature of heat exchanger modeling, which demands substantial computational resources and time. This paper presents the development of CFD modeling capabilities for predicting temperature distribution at duct outlet grills for defrost mode. Additionally, it assesses heater performance under maximum hot conditions. STAR-CCM+ software is employed to model the entire system, with the heater and evaporator core represented as porous

Ahmad, Taufeeq, Parayil, Paulson, Sharma, Nishant, Kame, Shubham, Jaiswal, Ankit, Goel, Arunkumar

A Study to Establish an Evaluation Method for Selecting Suitable Packing Adhesives for A/C Ducts to Ensure Sustained Adhesiveness in Thermal and Condensation Conditions over the Vehicle's Lifetime

2024-28-0096

09/19/2024

The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water

M, Amala Rajesh, Sonkar, Surabhi, Kumar, Mukesh

A Novel Methodology to Assess the Effectiveness of Passive Cabin Cooling Technology

2024-28-0111

09/19/2024

Today, almost all passenger vehicles are equipped with Mobile Air Conditioning (MAC) systems to provide thermal comfort to occupants. To enhance cabin cooling down rate, two approaches are possible viz. increasing the MAC system capacity or reducing heat ingress into the vehicle cabin. The first approach is likely to have a negative impact on energy efficiency. The latter approach considers the deployment of alternate passive cabin cooling technologies. Among these, the deployment of uniquely developed coatings on metal, plastic and glass surfaces of the cabin is one option. The assessment of such coatings is usually done only at severe ambient conditions (>40°C), which may not be sufficient. These coatings need to be validated across all climatic seasons of the year, for assessing their effectiveness on passenger thermal comfort. The current work along with simulation studies, takes into account additional parameters such as the ‘feeling of hotness’ when one enters a hot-soaked cabin

Deshmukh, Ganesh, Kulkarni, Shridhar Diliprao, Varma, Mohit, Jaybhay, Sambhaji, Kapoor, Sangeet, Tilekar, Pravin

A Case Study of Engine Cooling System Simulation and Modelling for Air Conditioning Application in a Medium Duty Truck

2024-28-0106

09/19/2024

Climate across India varies from extreme Cold to extreme hot. As an objective to improve comfort to drivers during summer, it is mandate by Indian Government to introduce Air Conditioning in Trucks from June 2025. Air Conditioning system includes Evaporator, compressor, Condenser and expansion units. Condenser needs continuous air flow to reject the absorbed heat from driver cabin to surrounding air. This is possible by directing air through condenser by an external fan. For this condenser is remotely mounted with an electric driven fan or directly to the radiator-fan system. In this paper a case study is presented where Cooling system of a Non AC Intermediate Commercial Truck is modified for Air Conditioning application. Condenser is mounted on the radiator and the additional heat load is managed by a minor change in the system. Fan is operated based on coolant temperature and with additional controls for Air Conditioning. Simulations are done in a Thermal management software “KULI

Kiran, Nalavadath, M S, Vignesh

In-Vehicle Evaluation of a Rule-based Look Ahead Controller for Mobile Air Conditioning: Impact on Energy Savings

2024-28-0112

09/19/2024

Energy efficiency in both internal combustion engine (ICE) and electric vehicles (EV) is a strategic advantage of automotive companies. It provides a better user experience that emanates amongst others from the reduction in operation expenses, particularly critical for fleets, and the increase in range. This is especially important in EVs where customers may experience range anxiety. The energetical impact of using the air conditioning system in vehicles is not negligible with power consumptions in the range of kilowatts, even with a stopped vehicle. This becomes particularly important in areas with high temperature and humidity levels where the usage of the air conditioning systems becomes safety factor. In such areas, drivers are effectively forced to use the air conditioning system continuously. Hence, the air conditioning system becomes an ideal choice to deploy control strategies for optimized energy usage. In this paper, we propose and implement a control strategy that allows a

Jaybhay, Sambhaji, Kapoor, Sangeet, Kulkarni, Shridhar Diliprao, Palacio Torralba, Javier, Locks, Olaf

Evaluation of Air Conditioning Hoses and Coupled Hose Assemblies using New Refrigerants or Refrigerant Blends

J3291_202408 (Current)

08/01/2024

SAE J3291 covers hoses and coupled hose assemblies intended for containing and circulating lubricant, liquid, and gaseous refrigerant in automotive air-conditioning systems. This recommended practice will be used to establish requirements for the validation of hoses, hose assemblies, or nonmetallic line assemblies with any new refrigerant or refrigerant blend being considered for use in automotive air-conditioning systems. The new refrigerants and blends covered by this document do not include current refrigerants R134a, R1234yf, and R152a. This document does not cover previously used refrigerant R12 nor refrigerants used in transcritical systems, such as R744. It is the system manufacturer’s responsibility to ensure that adequate compatibility testing is completed with new refrigerants, blends, and lubricant combinations together with intended hose materials. The recommended tests include, but are not limited to, volume swell, delamination, and rapid decompression. These tests are not

Interior Climate Control MAC Supplier Committee

The Effect of Battery Thermal Management System Unit on the Roof of a Bus on Passenger Air-Conditioning Performance

2024-01-5066

06/24/2024

While cooling comfort is important in city buses compared to other vehicles, it is also difficult to keep the cooling performance at a high level. Roof AC units used in commercial vehicles may vary in performance depending on many factors. Therefore, while the design works are in progress, there are some points to be considered while the units are in the packaging phase. These points are that the air used for condenser cooling in the air conditioner suction zone is at low temperature with high flow rate. In this study, it is aimed that the air conditioner and battery cooling unit placed on the roof of a bus developed by ANADOLU ISUZU are not adversely affected by each other. For this reason, in the related study, design and analysis studies were carried out to reduce the negative effects of the hot air coming out of the battery thermal management system (BTMS) in the cooling circuit when the air conditioner is activated. The aim of the study is to ensure that the air-conditioning unit

Küçükbayram, Hamdi

Acoustic VS Reliability. Case Study of Automotive Components Undergoing Vibration Endurance Tests

2024-01-2948

06/12/2024

During design development phases, automotive components undergo a strict validation process aiming to demonstrate requested levels of performance and durability. In some cases, specific developments encounter a major blocking point : decoupling systems responsible for optimal acoustic comfort performances. On the one hand, damping rubbers need to be soft to comply with noise, vibration & harshness criteria. However, softness would provoke such high amplitudes during vibration endurance tests that components would suffer from failures. On the other hand, stiffer rubbers, designed for durability purposes, would fail to meet noise compliance. The rubber design development goes through a double-faced dilemma : design with acceptable trade-off between NVH and durability, and efficient ways to develop compliant designs. This paper illustrates two case studies where different methodologies are applied to validate decoupling systems from both acoustic and reliability perspectives. The goal was

Bonato, Marco, Bennouna, Saad, Ravineala, Tudor

Dynamic Modelling and Validation of Hoses in an HVAC Circuit

2024-01-2923

06/12/2024

The structure-, fluid- and air-borne excitation generated by heating, ventilation and air conditioning (HVAC) compressors can lead to annoying noise and low frequency vibrations in the passenger compartment. These noise and vibration phenomena are of great interest to ensure a high passenger comfort of electric vehicles (EV). This publication describes the development of a numerical finite element (FE) model of the HVAC system and the simulation results of structure-borne sound transmission from the compressor via the HVAC hoses to the vehicle body in a frequency range up to 1 kHz. The simulation results were validated with measurements. An existing automotive HVAC system was fully replicated in the laboratory. Vibration levels were measured on the compressor and on the car body side of the hoses under different operational conditions. Additional measurements were carried out using external excitation of the compressor in order to distinguish between structure- and fluid-borne

Buchegger, Blasius, Sonnberger, Pius, Böhler, Elmar, Nijman, Eugene, Rejlek, Jan, Billermann, Robert, Krüger, Yannik

HVAC Blower: A Steady State RANS Noise Prediction Method

2024-01-2937

06/12/2024

In an ever-transforming sector such as that of private road transport, major changes in the propulsion systems entail a change in the perception of the noise sources and the annoyance they cause. As compared to the scenario encountered in vehicles equipped with an internal combustion engine (ICE), in electrically propelled vehicles the heating, ventilation, and air conditioning (HVAC) system represents a more prominent source of noise affecting a car’s passenger cabin. By virtue of the quick turnaround, steady state Reynolds-averaged Navier Stokes (RANS)- based noise source models are a handy tool to predict the acoustic power generated by passenger car HVAC blowers. The study shows that the most eminent noise source type is the dipole source associated with fluctuating pressures on solid surfaces. A noise map is generated from the noise source models data, giving indications of how changes in operating conditions affect the acoustic output of the machine throughout its operating range

Pietroniro, Asuka Gabriele, Kabral, Raimo, Huang, Zhongjie, Backman, Joakim, Knutsson, Magnus, Abom, Mats

A Study on the Combined Air Conditioning Condenser System for Ultra Fast Charging Time Reduction

2024-01-2399

04/09/2024

As regulations on exhaust emissions of automobiles are tightened in each country, the paradigm of the automobile industry is rapidly changing from internal combustion engine vehicles to electric vehicles, and consumers' interest in electric vehicles and sales volume are soaring. However, it is very inconvenient for consumers that electric vehicles take a considerable amount of time to charge compared to internal combustion engines, which can be refueled within minutes at gas stations. Therefore, shorter charging times are bringing electric vehicles to an inconvenience. It is the most important part in the development. The factors that determine the charging time of the electric vehicle include the capacity of the charger, the characteristics of the battery, Although many aspects such as charging control strategy are included, battery thermal management is one of the most influential factors in determining charging speed. In the case of an electric vehicle that can be charged at high

Jeong, Seong-Bin

A Method for Predicting Fatigue Life of Rubber Isolators at Power Spectral Density Load

2024-01-2261

04/09/2024

Rubber isolators are widely used under random vibrations. In order to predict their fatigue life, a study on the fatigue analysis methodology for rubber isolators is carried out in this paper. Firstly, taking a mount used for isolating air conditioning compressor vibrations as studying example, accelerations versus time of rubber isolator at both sides are acquired for a car under different running conditions. The acceleration in time domain is transformed to frequency domain using the Fourier transform, and the acceleration power spectral density (PSD) is the obtained. Using the PSD as input, fatigue test is carried for the rubber isolator in different temperature and constant humidity conditions. A finite element model of the rubber isolator using ABAQUS is established for estimating fatigue life, and model validity is verified through static characteristic testing. Dynamic responses of the rubber isolator at frequency domain are calculated if a unit load is applied. The estimated

Yao, Qishui, Li, Min, Zhang, Licheng, Yue, Zaiqin, Shangguan, Wen-Bin

XiLS (X in the Loop Simulation) Based Thermal Management Development

2024-01-2272

04/09/2024

The significance of thermal management performance in electric vehicles (EVs) has grown considerably, leading to increased complexity in thermal systems and a rapid rise in safety and quality-related concerns. The present real-vehicle-based development methods encounter several constraints in their approach when dealing with highly complex systems. Huge number of verification and validation work To overcome these limitations and enhance the thermal system development process, a novel virtual development environment established using the XiLS (X in the Loop Simulation) methodology. This XiLS methodology basically based on real-time coupling between physical thermal system hardware and analytical models for the other systems of vehicle. To control vehicle model and thermal system, various options were realized through hardware, software and model for VCU (Vehicle control unit) and TMS (Thermal management system) control unit. With XiLS evaluation environment as the foundation

Lim, Taewoong, Baek, Junho, Dongmyeong, Lee, Jeon, Jee Hwan, Lee, Hyeonseob, Park, Junhyeong, Myeong, Hanseung, Kim, Myeongwoo, Choi, Seockhwan

Humidity Controlled Evaporative Cooler for Cooling of Automotive Cabin

2024-01-2580

04/09/2024

The discussed invention is centered on the evaporative cooling of a vehicle cabin, introducing a novel concept of humidity control. Unlike conventional Air Conditioning (AC) systems that operate on the Vapor Compression Refrigeration Cycle (VCRC), which tend to be costly and contribute to higher fuel consumption due to the engine-driven compressor in automobiles, there is currently no other Original Equipment Manufacturer (OEM) fitted cabin cooling option available to address this issue. This paper introduces the idea of a humidity-controlled evaporative cooler. The objective of humidity control is achieved through a controller unit that receives feedback from a humidity sensor, subsequently regulating the operation of the water pump. The ambient air is passed through a humidified honeycomb pad, cooling through the principle of evaporation. To prevent any leftover water droplets from entering the cabin, a polyester nonwoven filter has been integrated into the system. This invention not

Dube, Devashish, Upkare, Piyush Pradip

A Preliminary Study on the Evaporative Cooling System for FCEV

2024-01-2406

04/09/2024

The existing FCEV have been developed with only a few vehicle models. With the diversification of both passenger and commercial FCEV lineups, as well as the increasing demand for vehicle trailer towing, there is a growing need for high-capacity fuel cell stacks to be applied in vehicles. However, at the current level, there are limitations and issues that arise, such as insufficient power output and reduced driving speed. As a results, the importance of thermal energy management has been increasing along with the increase in required power. Traditional cooling performance enhancement methods have mainly focused on developing increased hardware specifications, but even this approach has reached its limitation due to package, cost and weight problem. Therefore, it is essential to develop a new cooling system to solve the increases in heat dissipation. This study aims to develop an evaporative cooling system using water as a by-product of the stacks, and to identify the effects of

PARK, Ui Joon, Kwon, Soon Beom, Choi, Kyung Jun, Lee, Gil Woo, Oh, Dong Seok

Using Natural Refrigerants Propane (R290) & Carbon Dioxide (R744) as Direct & or Indirect Heat Pump Systems to Address PFAS Issue

2024-01-2876

04/09/2024

Per - and polyfluoroalkyl substances – known as PFAS are man-made chemicals that do not occur naturally. PFAS are widely used, long lasting chemicals, components of which break down very slowly over time. Scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals. Because of their widespread use and their persistence in the environment, many PFAS are found in human and animals’ blood all over the world and are present at low levels in a variety of food products and in the environment. PFAS are found in water, air, fish, and soil at locations across the nation and the globe. Both refrigerants (HFC-134a & HFO-1234yf) that are currently used in mobile air conditioning systems (MACS) create PFAS. Hence, various countries are looking into banning chemicals that create PFAS. Natural refrigerants are being proposed as alternative refrigerants as they do not create PFAS. Hence, Propane (R290) and Carbon-Dioxide

Mathur, Gursaran

Influence of Working Conditions and Operating Parameters on the Energy Consumption of a Full-Electric Bus. Experimental Assessment

2024-01-2174

04/09/2024

Given the growing interest in improving the efficiency of the bus fleet in public transportation systems, this paper presents an analysis of the energy consumption of a battery electric bus. During the experimental campaign, a battery electric bus was loaded using sand payloads to simulate the passenger load on board and followed another bus during regular service. Data related to the energy consumed by various bus utilities were published on the vehicle’s CAN network using the FMS standard and sampled at a frequency of 1 Hz. The collected experimental data were initially analyzed on a daily basis and then on a per-route basis. The results reveal the breakdown of energy consumption among various utilities over the course of each day of the experiment, highlighting those responsible for the highest energy consumption. Subsequently, the relationship between the energy consumption of the traction motor and the climate control system was investigated concerning environmental parameters

Belloni, Mattia, Tarsitano, Davide, Sabbioni, Edoardo

Further Analysis of the Blockage Phenomenon during the Testing of Bluff Automotive Bodies in Closed Wall Wind Tunnels – Revised and Updated

2024-01-2534

04/09/2024

The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been impractical if not impossible to experimentally analyze the effects that are occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier work by the author and similarly to that study uses the CFD (computational fluid dynamics) analysis of several bodies of differing configurations to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, forces and force increments experienced by the vehicle model. This is accomplished by executing a series of CFD configurations with varying sized cross sections from 0.2% to 16% blockage enabling an approximation of free air conditions as a reference. The

Gleason, Mark, Riegel, Eugen

A Switching Control Strategy for Multiple Heating Modes Based on the Integrated Thermal Management System of Electric Vehicles

2024-01-2233

04/09/2024

To reduce the heating energy consumption of electric vehicles in winter, a switching control strategy for multiple heating modes formed by three heat sources, including air, motor waste heat, and positive temperature coefficient (PTC) heaters, is designed. Firstly, an integrated thermal management system (ITMS) simulation model for the heat pump air conditioning system, battery thermal management system, and motor thermal management system is established based on the AMESim software. Secondly, the influence of ambient temperature and motor outlet coolant temperature on the heating performance of three cabin heating modes is studied. Specifically, the three cabin heating modes include the pure motor waste heat source heat pump mode, the pure air-source heat pump mode, and the dual heat source heat pump mode with waste heat source and air source. Based on the analysis results, the opening and closing strategies for the three cabin heating modes are discussed. The optimum mode of using

Zhang, Feng-Ting, Zhang, Zai-Cheng, Liu, Xiaoang, Shangguan, Wen-Bin, Huang, Yu, Li, Guoqiang

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