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Electrical Air Conditioning Systems for 42 V vehicles will provide many benefits in terms of Environment protection, car Architecture, cabin Comfort and overall Safety. E-A/C Systems essentially differ from conventional ones by the use of electrical compressors. First of all, they will be particularly well adapted to new powertrains, helping to make them more environmentally friendly. Accurate control and high efficiency under the most common thermal conditions will reduce the A/C impact on fuel consumption. Besides, higher sealing integrity will cut emissions of refrigerant during normal operation and maintenance. Secondly, the use of an electrically driven compressor (EDC) will suppress a belt, and will reduce the packaging constraints. This will help to design new vehicle architectures. Thirdly, the electrification of air conditioning will allow better thermal comfort. In particular, E-A/C Systems provide a good opportunity for cabin pre-conditioning.

Current systems of air diffusion inside the car cabin are leading in some conditions to passenger discomfort. To solve this problem our company has developed a new concept of air diffusion. It consists in an air distribution system composed of a wide central air diffusion area on the top of the instrument panel and two lateral outlets. To evaluate the comfort performances of the concept a methodology based on experiments, simulation and subjective evaluation has been defined and used. The comparison between the current air diffusion and the new one shows a significant impact on the driver's and passenger's comfort. The purpose of this paper is to describe the methodology developed to analyze the air diffusion impact on the comfort and the improvements obtained by the new concept.

This paper presents the results of a study into an innovative system using a new type of technology for the automotive domain with the aim of improving passengers' thermal comfort. A study of the thermal interactions between the cabin and its passengers shows that radiative heat transfers clearly contribute to the passengers' thermal discomfort during the first few minutes of a vehicle's use. Therefore, to limit this kind of heat exchange, an innovative A/C system combining a conventional automotive A/C loop and a Heat Pipe Dashboard Panel has been developed. This reduces the dashboard temperature rapidly, immediately after starting the A/C system (70°C to 10°C in 3 min).

This paper presents the results of a study of the various thermal interactions between the automotive passenger compartment and the passengers, using the equivalent temperature concept. Radiative and convective heat exchanges are described. A technical proposal to improve the thermal comfort of passengers is also made.

Providing adequate level of comfort is the main objective of an HVAC. This kind of information is not very useful at the end of a study and also is very expensive to obtain if only an experimental approach is used. In fact, the analysis of comfort problem is the right place for a model. The paper will concern the development of a in cab thermal comfort numerical model. The first part of the development is only achieved for the winter outside conditions. The model is developed in order to predict the local thermal sensations of the car driver according to the thermal conditions provided by the heating system. A lot of experiments have been lead in the VALEO wind tunnel to complete and validate the model. The development perspectives concern the summer outside conditions. This study supported by VALEO Climate Control and PSA PEUGEOT CITROEN, has been performed by the Laboratory LESETH (University of Toulouse).

The arising “Stop&Go” function contributes to the reduction of new cars fuel consumption. However, as the engine shuts off when the car stops, cabin heating and air conditioning cut off because they are belt driven. This paper first describes the cabin temperature evolution when it occurs. It shows that solutions must be found in order to guarantee passenger comfort maintaining. Different concepts are presented, built on fuel, electrical or thermal energy storage. A comparison is provided, showing that the latter should be preferred. The biggest remaining issue for long stops is storage itself.

The paper deals with an innovative system using a new type of technology for the automotive domain in order to improve rear passengers’ thermal comfort. This device is an add-on thermal module plugged into the headliner of a car. This kind of product has been developed and integrated in a car for validation. Tests have been performed in terms of thermal comfort improvement using a human panel. They show a real effect at the head level of the rear passengers in summer and in winter. Moreover, it offers independent control to the left and right rear passengers in terms of mass flow and temperature with easier in-vehicle integration for the car makers than a rear HVAC.