Assessment of local and overall vehicular thermal human comfort and sensation states for transient, non- uniform conditions under variant air velocity levels

Abstract

ABSTRACT The main purpose of any vehicular climatic control in terms of heating and air conditioning (AC) systems is to achieve maximum thermal human comfort with energy efficient. Therefore, it is important to analyse the temperature distribution and air-flow field in the cabin compartment to achieve the highest and rapid human comfort. This paper adopted a Berkeley human comfort model to show the behaviour of a vehicular human sensation and comfort at different airflow velocity levels. A temporal history, local sensation (LS), and comfort (LC) were analysed for different body segments with the addition of the overall sensation (OS) and the overall comfort (OC) inside the passenger compartment under summer period weather conditions. This study revealed that: because of the air velocity plays crucial impacts on both convection and evaporation mechanisms which directly effects on the heat losses from the body and thermal human comfort, the controlling of air movement with the temperature helps the environmental cabin to achieve the comfort zone faster than the sole control of the temperature only. When activated the air conditioning systems, the vehicular environmental parameters will change dramatically and a rapid transient occurred especially in the first few minutes.