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The Indian automotive industry is going through a rapid transformation phase. Regulatory emission norms such as, migration from BSIV to BSVI engine, increased adoption of μ-hybrid, full electric and autonomous cars are examples of such rapid transformation. The upgradation of internal combustion engines for compliance with new regulatory norms (e.g., from BSIV to BSVI) has caused a significant change in the automotive acoustic performance. As the powertrain system are being upgraded and getting quieter, the on-board Heating, Ventilation and Air-Conditioning system (HVAC) system emerges as one of the prominent noise sources which strongly influences overall refinement levels inside the cabin. This in turns is affecting overall feeling of passenger’s comfort. The HVAC system of an automobile is a compact and yet a complex system designed to provide thermal comfort inside the car cabin.

With the advent of new technologies and rigorous research and development work going on vehicle engines, cars are becoming quieter and more refined than ever before. This has led to the observance of subjective noises being audible to passenger compartment which were earlier masked behind engine noise. The vehicle HVAC system has several moving parts and transient flow of refrigerant which can cause certain types of irritant noise. Thus having a refinement in of air-conditioning (AC) system would aid us in cutting down on this parasitic noise source. Thus noise refinement should be one of the important parameters during the design and development of the Heating, Ventilation and Air-Conditioning (HVAC) system for a vehicle program.

Unfavorable climates, fatigue, safety & deprived sleep of driver’s leads to use of AC system for their quick thermal comfort during night with engine ON. This scenario is very critical from a human’s safety & vehicle functionality point of view. This also consumes an additional 10-15% of fuel requirements in AC running conditions. So, to address the social problems of driver’s sleep and pollution-free environment by reducing the use of fossil fuels, there is a need for alternative techniques for air cooling which work during engine OFF condition. Various alternative options for air cooling have been reviewed. Accordingly, the packaging flexibility of phase change material (PCM) technology makes it easy to implement, yet effective usage of large quantity stored PCM, needs optimization. This paper proposes a design of a hybrid air conditioning system for sleeper commercial vehicles using a combined conventional compression and phase change material.

This paper explains about the design & development of IHX for HCVs segment and vehicle level validation to get the actual benefits with this technology. Moreover, the data observed during vehicle testing also indicates the improvement in AC System Performance. This experiment was done on HCV platform vehicle with multiple actual test conditions with two designs of IHX. Final result shows the optimized AC system design to achieve better efficiency.

This paper and presentation compare the thermal, economic and climate performance of existing direct expansion motor vehicle air conditioners (DX-MACs) using hydrofluorocarbon (HFC)-134a (global warming potential (GWP) =1300) with secondary-loop MACs (SL-MACs) using hydrofluoroolefin (HFO)-1234yf (GWP < 1) and HFC-152a (GWP = 138), both of which satisfy the European Union (EU) and Japan F-gas regulations and are listed as acceptable by the US Environmental Protection Agency (US EPA). In addition to a technical review of the SL-MAC system, the paper includes a part-by-part system manufacturing cost comparison and itemized ownership cost comparison taking into account fuel savings and reduced maintenance. The paper is timely because the Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer now requires both developed and developing countries to phase down the production and consumption of HFCs and at the same time encourages increases in energy efficiency.

Enriched ventilation and driver assistance systems which plays vital role in human thermal comfort and safety, are now necessities for the whole automotive sector. For faster cabin thermal comfort, air circulation around occupant’s body reveals higher cabin comfort index. In India natural and forced ventilation system is predominantly used in commercial vehicles as an economical solution for achieving interim cabin comfort over air conditioning system. Presently used forced ventilation system consist of electrically driven blower motor to remove stale air around human body which is adding alternator load and thus affects fuel economy. Remarkably, 22% of such auxiliary electrical load is taken by electrical components from engine generated power. In order to enhance cabin thermal comfort and conceivably reduce power usage, an effective air flow control system is need of hour.

Commercial electric vehicle air conditioning system keeps occupants comfortable, but at the expense of the energy used from the battery of vehicle. Passengers around the world are increasingly requesting buses with HVAC/AC capabilities. There is a need to optimise current air conditioning systems taking into account packaging, cost, and performance limits due to the rising demand for cooling and heating globally. Major elements contributing to heat ingress are traction motor, front firewall, windshield & side glasses and bus body parts. These elements contribute to the bus’s poor cooling and lack of passenger comfort. This topic refers to the reduction of the heat ingress through usage of different glass technology like IR Cut & solar green glass with different types of coating.

In an automotive air conditioning system, evaporator is well designed for effective heat transfer between refrigerant and air flowing over the evaporator. This cold and dehumidified air obtained at evaporator is then supplied to passenger cabin. There are various parameters like air flow over evaporator, ambient temperature, humidity condition and condensate drain mechanism which can cause frost formation over the evaporator core. This study presents the probable causes of frost formation and their effects on the performance of evaporator and thus affecting overall performances of the automotive air conditioning system. In this study effect of variation in four major independent factors such as poor response of thermistor, undercharged refrigerant system and overcharged refrigerant system, drop in air flow by blower due to clogged air-filter, and also the effect of type of compressor has been studied.

With the passage of the Kigali Amendment to the Montreal Protocol, HFC-134a refrigerant will be phased down in all markets worldwide, including those where automotive companies have been slow to embrace HFO-1234yf. Engineers are currently being challenged to design MAC systems using alternate low GWP refrigerants that are allowed by regulations, and are simultaneously cost-effective to manufacture, energy efficient, safe, reliable, affordable for consumers, and also suitable in electrified vehicles.