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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).

Vehicles wind shield are designed to provide a clear visibility in winter as its one of the most important requirement for the comfortable and safe journey. In extreme winters, wind shield of vehicle is covered with layer of ice and if frosted happened, results in reduces the visibility distance. To increase the visibility and providing the comfort to driving the vehicle, heater is used in vehicle as an integrated part of vehicle HVAC System. When the blower air passes through heater, air temperature gets increased. When the hot air is injected through grill at designed angle of injection and at selected air velocity on wind shield surface, ice on wind shield melting due to convection heat transfer phenomenon and thus achieved a clear windshield glass and clear visibility at driver and at co-driver area.

Adequate visibility through the vehicle windshield over the entire driving period is of paramount practical significance. Thin water film (fog) that forms on the windshield mainly during the winter season would reduce and disturb the driver’s visibility. This water film originates from condensing water vapor on inside surface of the windshield due to low outside temperatures. Primary source of this vapor is the passenger’s breath, which condenses on the windshield. Hot and dry air which impinges at certain velocity and angle relative to the windshield helps to remove the thin water film (defogging) and hence improves driver’s visibility. Hence a well-designed demisting device will help to eliminate this fog layer within very short span of time and brings an accepted level of visibility. An attempt is made here to design and develop a demisting device for a commercial vehicle with the help of numerical and analytical approach and later on validated with experimental results.