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In perspective of the incoming CO₂ emission regulation, the on-board heat management is becoming even more relevant to assure the engine performance improvement minimizing the impact on the vehicle lay out, cooling drag and cost. The paper highlights the benefit of dual-level heat rejection system where the conventional front module is replaced by two coolant-to-air exchangers and where the charge air cooler and condenser are liquid-cooled. This approach allows to review the engine bay design allowing a deeper integration level: the charge air cooler can be integrated in the air intake manifold while the condenser can be placed near the compressor minimizing the tube lengths and refrigerant charge. In addition, the coolant thermal inertia reduces the temperature fluctuations of the engine intake air temperature.

The B-COOL project, funded by the European Union, is devoted to the development of low cost and efficient R-744 system for small cars. In the framework of this initiative a Fiat Panda and a Ford Ka prototype have been realized adopting two different R-744 systems and a testing procedure has been identified and adopted to qualify the vehicles in terms of fuel consumption and thermal comfort performance. The Project started in March 2005 and ended in November 2008, this paper presents the major project outcomes on R-744 mobile air conditioning systems (efficiency and related fuel consumption and LCCP, costs, architecture) synthesizing the remaining technology open issues

The air conditioning system is becoming more and more a competitive issue, moving from optional to standard vehicle equipment. Therefore, also thermal comfort level is moving from simple air temperature measurement to a more systemic approach, where the contribution of every element of the car cabin has to be taken in account. Improving contact thermal sensation with the seat is one of the main issues to improve overall thermal comfort in transportation. A method has been defined to assess the perceived thermal quality of seats taking into account the sweating human thermoregulatory process. The method is based on a thermal manikin representing a torso able to simulate in a portion of the back the sweating phenomena. The first part of the paper is focused on the instrument and developed measuring method description. The second part is dedicated to detail the correlation between experimental measurements and subjective quality index obtained during an extensive on-road panel test.

The customer increased sensitivity to air quality problem and the natural influence of smell on human behavior affect the purchasing decision as the opinion on the vehicle quality during its life. So the olfactory quality is an even more important issue. Since the early 80's the car manufacturers have been working on the olfactory quality assessment using panel tests with trained or untrained sniffers. The subjective tests are expensive and require a not negligible time to be organized. The Centro Ricerche FIAT evaluated the applicability of an electronic nose to assess the odor quality and compared the obtained results with the votes of a jury.

The cabin comfort is one of the most competitive issues in the automotive area of business. The thermal comfort and the environmental well-being are fundamental performances that contribute to generate the more general idea of perceived quality. The CRF developed in the past the concept so-called “healthy bubble” that was implemented in the Lancia Dialogos concept car. The passengers are surrounded by an air bubble, created by generating low velocity air flows, that are diffused through the interior panels and components (e.g. dashboard, roof, back of the seats, etc.), and by surfaces temperature control (e.g. carpet, seats, etc.). At present the original idea has generally been accepted, and different solutions to diffuse air and to control surface temperature of vehicle interiors have been proposed by some automotive supplier.

External Control Compressors (ECC) with variable displacement are available on the market and permit to create smart control system, taking into account both cooling needs of the cabin and the engine running speed. With a limited number of sensors it is possible to create new algorithms to control the refrigerant mass flow rate. The paper presents a reference line of a mobile air-conditioning system using a variable displacement compressor and the improvement associated with the new control system. The tests have been performed according to the European regulatory reference cycle in order to measure fuel consumption of vehicles taking into account both urban and extra-urban cycles. It is essential to analyze mobile air-conditioning systems energy performances, referred to realistic conditions taking into account the quick variations of engine speed during various driving cycles.

The heating and cooling systems are an important issue in the development of fully electric vehicles (FEVs). On the contrary to vehicles with thermal engines, in FEVs there is almost no waste heat available for the heating of the cabin or for the window de-icing and defogging. The cooling of the cabin also demands a large amount of energy. Due to the high power consumption, the heating and cooling of FEVs is a compromise between thermal comfort and vehicle range. The aim of this work is to present the European project ICE (2010-2014) [1] which focuses on the development of an efficient air-conditioning and heating system based on a magneto-caloric heat pump and on a new system architecture to fulfill the thermal comfort requirements of an electric minibus. The system will be installed and demonstrated in a Daily Electric Mini-bus from IVECO-ALTRA.

Automotive world is rapidly changing driven by the CO2 emission regulations [1], [2] worldwide asking for a dramatic fuel consumption reduction. The on board thermal management has a relevant role influencing the front vehicle design and sizing to assure the right heat rejection capacity and being crucial to guarantee the on board system efficiency and reliability. In this context the dual level cooling system with water cooled charge air cooling is a clear trend leading to a new generation of systems [3, 4]. This paper describes a compact solution to effectively implement a dual cooling loop system with water cooled charge air cooler and water cooled condenser on small/subcompact cars giving the opportunity to integrate additional modules (e.g. in case of hybrid powertrain) to the secondary loop.

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.