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For an efficient automotive AC system it is very essential to ensure uninterrupted and consistent airflow and temperature at the vent exit to help achieve the comfortable cabin space. This certainly requires temperature sensor to position at lowest possible temperature on heat exchanger and uniform flow distribution over it. However the uneven distribution of airflow on evaporator entry face leads to lowest temperature and sometimes goes undetected. This causes the condensate to get freezed and then frosting occurs at the core surface. Eventually a substantial portion of evaporator face gets choked and gradually airflow reduces and evaporator exit air temperature shoots up. Hence it is very important to prevent the frosting on evaporator core so to have uninterrupted airflow and adequate cooling in the passenger compartment. The present paper investigates the reasons for frosting occurring in one of the hatchback vehicle in bench test.

Automotive heating ventilating and air conditioning (HVAC) noise is a very big concern for original equipment manufacturers (OEM) and suppliers. It turns out to be more challenging as the demand for acoustic comfort is increasing day by day. Many times an existing HVAC with some minor changes (mostly the vehicle fitment points) is proposed for face-lift vehicle but the performance expectation is far beyond the existing one due to market demand. One of the critical requirements is enhanced sound quality. To achieve that either experimental testing or numerical simulation is adopted. In either of these cases, it ends up with high number of experiments or increased simulation cost due to aero-acoustic simulation. Hence a combined approach is followed in order to investigate and improve the noise sources of an existing HVAC. The present paper describes this approach in details by doing numerical flow simulation followed by experimental investigation.

The aim of this paper is to optimize flow distribution on various ports of the ventilation unit. To improve the passenger comfort, ventilation unit need to be redesigned to get the uniform distribution in all ducts. There were challenges for the design modification on the unit to meet the distribution. The major challenge was to meet the distribution on the duct outlet without doing any design changes on the ducts. Hence the adapter which is the intermediate part between the blower and duct assembly is modified and simulation is done on the various design changes by changing the design of the adaptor part. CFD analysis is carried out on the ventilation unit with iterative design changes and achieved the target airflow and distribution. The analysis has been carried out on STAR CCM+ software.

A Finite Element Method (FEM) is used to determine the modal frequency and structural integrity of the automotive condenser assembly, whereas the experimentation (modal and dynamic) are performed using electro-dynamic vibration shaker for vibration durability. In this paper, numerical and experimental modal & dynamic analysis are discussed to derive the modal properties (mode shapes & modal frequencies) and dynamic properties (stresses & deflections) of condenser assembly. The effects of vibration occurring due to dynamic interaction between vehicle and road, vibration transmitted from machinery to its supporting structures thereby interfering with their performance, damage as well as malfunction and failure due to dynamic loading and cyclic loading. In this work, author compared modal frequencies as well as the life cycle of the condenser assembly through FEM and experimentations.

As the global warming due to carbon footprint is very alarming, vehicle emissions are getting stringent day by day. In such situation vehicle hybridization or fully electric vehicles are of obvious choices. However in any of the cases the battery cooling is a big concern area. As the heat produced by the battery need to be dissipated in the long run, it is of utmost need to develop and understand the battery cooling system. Present paper describes the experimental investigation of a battery cooling circuit. A complete bench comprising of both primary and secondary circuit is used for the testing. The primary circuit has a cooling unit with TXV, condenser and electric compressor run by high voltage. The secondary circuit consists of a chiller (integrated with TXV) unit responsible for battery cooling. The whole circuit typically resembles with one of dual air conditioning unit and uses one of known refrigerant used in vehicle AC system.

Automotive Air Conditioning is the process of removing the heat and moisture from the interior of an occupied space to improve comfort of occupants. A condenser is a device or unit used to condense refrigerant from its gaseous to its liquid state, by cooling it. In so doing, the latent heat is given up by the substance and transferred to the surrounding environment. It is made of Aluminum Alloy Material and subjected to very high internal stresses due to refrigerant pressure, thermal / inertia and dynamic load. In order to evaluate the structural integrity of the condenser assembly under these loading conditions, operating frequency should be far away from the resonance frequency and component design should be robust to sustain external excitation load coming from the engine & road. The above design evaluation criteria is also applicable for piston of AC’s reciprocating compressor.

A Automotive Air Conditioning is the process of removing heat and moisture from the interior of an occupied space to improve comfort of occupants. Heating, ventilation, and air conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC systems can be used in both domestic and commercial environments. It is made of Plastic material and fitted inside the front dash panel, therefore, subjected to very high vibrations coming from engine & road. The main Objective is to remove unwanted vibrations by altering the modal frequency. From the FEA, very high deflection, cause unwanted vibrations reported on the HVAC assembly at low frequency (1st modal frequency) under dynamic conditions. Then, improved the design by adding the stiffeners on the flange to minimize that high deflection. Thereafter, modal frequency has been increased and reduced the high deflection.

As the current market trend is emerging towards the compactness, better comfort and less emission, it is quite important that factors contributing to these aspects should be kept under control and maintained within the desired range. Heating ventilation and air conditioning (HVAC) noise is one such factor which significantly contributes in occupants’ acoustic comfort. It creates discomfort to the occupants while HVAC is in operation and eventually lead to fatigue. In a HVAC, there are several different types and sources of noise which cumulatively impacts the overall noise level. However, few of them are quite prominent and has maximum impacts on overall noise. It is very important to identify and measure these sources in order to take appropriate countermeasure to mask or eliminate them. In order to identify and measure the noise sources, various methods are used.

The present paper outlines the selection and numerical modeling of a high performance and efficient blower motor fitted in an automotive Heating ventilation and air conditioning (HVAC) system. In today’s scenario blower motor is present in almost every car whether fitted with AC system or only blower system. The selection of a blower motor is very important in terms of delivering right amount of airflow with minimum consumption of electric power. As the power consumption goes up it may impacts in indirect green house gas (GHG) emission from a vehicle. While it does so e.g. fulfills HVACs’ airflow need, it generates some amount of heat which is very detrimental for its life and overall performance as well. Also the generated heat may lead to increase in temperature of the main stream air flow causing reduction in the cabin cooling and eventually hampers the comfort level.

With stringent requirements of fuel efficiency and emissions, the airflow and thermal management within the under-hood environment is gaining significance day by day. While adequate airflow is required for cooling requirements under various vehicle operating conditions, it is also necessary to optimize it for reduced cooling drag and fan power. Hence, the need of the day is to maximize cooling requirements of Condenser, Radiator, CAC and other heat exchangers with minimal power consumption. To achieve this objective and due to the complicated nature of 3D flow phenomenon within the under-hood environment, it is useful to perform 3D CFD studies during preliminary stages to shorten design time and improve the quality and reliability of product design. In this paper we present the results from a CFD under-hood analysis that was carried out for design, development and optimization of a CRFM (Condenser, Radiator and Fan Module).

Automotive heating ventilating and air conditioning (HVAC) noise is becoming a big concern area as the demand for acoustic comfort increases day by day. Vehicles are manufactured in recent years with quieter powertrain, reduced body leakage, better suspension. The other quieter technologies like electrification, hybridization of vehicle further complicate the whole subject of vehicle cabin noise issue. The HVAC noise is the major noise source inside the cabin. Hence designing a HVAC with very low sound pressure level is quite challenging and poses many difficulties in meeting other basic performances due to certain trade-off while meeting the noise requirement. However in recent years engineers have done extensive research and come up with various feasible and non-feasible solutions in order to reduce the HVAC noise significantly.

As the automotive industry is transitioning from conventional engine driven to electric battery driven, many of the vehicle aggregates are getting re-engineered and changing accordingly. Being air-conditioning manufacturer one of the aggregates that needs attention and focused effort is the Heating Ventilation and Air Conditioning system (HVAC). Acoustic comfort of electric vehicle gets impacted due to the HVAC noise in absence of engine and hence other noise sources becomes prominent which were earlier masked by the engine noise. It is important to understand the HVAC noise sources for implementing right countermeasures for masking the noise. There are three methods of noise source identification namely acoustical duct method, cocooning or lead covering method and near field method. Out of these method, acoustical duct method and near field methods are used for minor and major noise identification in this study.

As HVAC noise is becoming one of the key factors to end users in terms of enhanced comfort, it is important to understand and evaluate various noise sources of HVAC in details. With detailed understanding of various sources, it becomes easier to take appropriate countermeasures in design and subsequently eliminate. There are many methods available in industry to investigate the noise sources in details however those options are expensive and time consuming and require deep understanding of the acoustic. Acoustical duct methods are one such method which proves to be very much helpful in identifying the noise sources from different aggregates like kinematics mechanism, door/damper, servomotors, heat exchangers etc. These sources are typically defined minor noise sources. The present paper describes the detailed investigation of those minor noise sources through the use of acoustical duct method. An existing HVAC from passenger car was considered for this study.

Compressor plays an important role in Automotive Air Conditioning (AC) System. It compresses the low pressure refrigerant and discharges the high pressure refrigerant vapour to condenser. Compressor performance mainly depends on two parameters, compressor oil and refrigerant gas charge quantity. Compressor oil is used to lubricate the movable parts in reciprocating compressors. Compressor oil is miscible in refrigerants in liquid state and amount of oil present in compressor increases the life of compressor. But, huge amount of oil may also reduce the thermal performance of system. Minimum gas quantity gives poor cooling performance and due to maximum quantity, increasing suction/discharge pressures, results in more compressor work and low cooling. This paper discusses the experimental analysis of refrigerant quantity, oil quantity in different ratios to improving the cooling performance of a passenger vehicle. Experimentation was conducted on 7 seater passenger car (hatchback).