In this research, to improve the automotive indoor-air quality, the reduction characteristics of automotive indoor pollutants were investigated for various RFRs and air flow rates, and effective operating conditions were suggested. An experimental correction equation was deduced to consider the effect of leakage using the equation for the RFR, and its validity was reviewed. Based on the numerical results, the following conclusions can be made. (1) The RFR for the automotive HVAC system is not proportional to the opening angle of the recirculation-mode door. The recirculation flow rate is always greater than the fresh-air inflow rate. In addition, as the air flow rate of the entire system increases, the recirculation flow rate increases at the same RFR. (2) An experimental correction equation for the leakage flow was defined using a polynomial regression, and it was verified by comparing the experimental results with the numerical results obtained through this equation. The maximum error between experimental and numerical results was less than 10%. (3) For various air flow rates and RFRs of the automotive HVAC system, the time required to reduce the gas concentration to the recommended indoor concentration level of 1000 ppm was computed. The results indicate that the time required increases linearly with increasing RFR in the range 0-50% for all operating flow rates (the time required for RFRs of 25% and 50% are about 1.4 times and 2.2 times higher respectively than that for an RFR of 0%). However, the time required is not linearly proportional for an RFR above 50%. (4) Comparison between an RFR of 25% at an operating flow rate of 145 m3/h and an RFR of 75% at an operating flow rate of 538 m3/h indicates that these cases show similar pollutant reduction rates in the automotive cabin. This finding suggests that the decreased RFR is more effective than the increased air flow rate in improving the automotive indoor-air quality. (5) If detection sensors are to be installed in the automotive cabin based on the strict criteria for an automotive HVAC system vent mode, it is recommended that the sensors be installed at the floor of the driver seat since the concentration of pollutant gases is the highest at this location. (6) In this study, the reduction characteristics of automotive indoor pollutants were evaluated on the assumption that the outside air is clean. In the case when the outside air is polluted, however, an additional evaluation of the reduction characteristics is needed according to the filter performance.


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    Title :

    Estimation of the air quality of a vehicle interior: The effect of the ratio of fresh air to recirculated air from a heating, ventilation and airconditioning system


    Additional title:

    Abschätzung der Luftqualität im Fahrzeuginnenraum: Einfluss von Mischungsverhältnis der Frischluft auf Umluft aus dem Heizungs-, Belüftungs- und Klimatisierungssystem


    Contributors:
    Seo, Jinwon (author) / Choi, Yunho (author)


    Publication date :

    2013


    Size :

    11 Seiten, 10 Bilder, 5 Tabellen, 13 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English