The main motivation behind research on control of the thermal environment inside a vehicle cabin, is since long time thermal comfort for the passengers. However, the consequences of bad thermal control in vehicle cabs go beyond the aspect of personnel thermal comfort: the processes of driver sleepiness and fatigue, two major causes for traffic accidents worldwide, are unambiguously
influenced by the present thermal comfort. This research intends to make a start with the integration
A new standard, ISO/DIS 14505 is under preparation, dealing with the assessment of the thermal environment in vehicles, based on the equivalent temperature. The scope of this paper is to demonstrate the different results obtained when evaluating the thermal environment inside a vehicle, using the three well known parameters, air temperature, operative temperature and equivalent temperature. The tests were carried out in the winter season during heat-up of the vehicle cabin.
Equivalent temperature is a thermal index used today for assessment of the thermal comfortin vehicles. Prediction of the percentage of people dissatisfied by the thermal environment iscalculated by implementing equivalent temperature in the PMV/PPD thermal index. In this work,PMV/PPD and PD (draft rate) indices are compared for vehicle conditions, with respect to air velocity and turbulence intensity. Results indicate that turbulence intensity must be taken in consideration for higher air velocities and that PD is the predominant thermal index after a certain air velocity is reached.
The paper presents experiment results of emission rates of HCHO from Medium DensityFiberboard (MDF, JIS grade E2) using three different test chambers. In this study, a full-scale stainless steel test chamber (19.68m3), a boundary layer type small test chamber (0.4m3), and a field and laboratory emission cell (FLEC, 3.510-5m3) were used. The coefficient of air change performance within the three test chambers was examined by CFD analysis. The convective mass transfer coefficient of HCHO from MDF was computed by CFD and the emission experiment.
An experimental study was conducted in a field environmental chamber with the aim of comparingceiling-based mixing ventilation (MV) system and under-floor supply system (UF) from the perspectives of indoor air quality and thermal comfort. Six tropically acclimatized female subjects participated in the experiments and they were required to complete a set of questionnaire pertaining to IAQ and thermal sensation every 20 minutes during each exposure of 2 hours.
This paper reports the effect of adsorptive building materials in reducing formaldehyde inindoor air. Although some studies have reported that adsorptive building materials are effective inreducing concentrations in chamber experiments, there are few studies which are carried out in actual room. In this paper we examine the reduction effect of changing the surface area of the adsorptive material in a room and the most effective arrangement of the material. We confirmed that the reduction effect is not always proportional to the adsorption surface area.
For underfloor air distribution (UFAD) systems, more rapid mixing of the supply air with ambient airis desirable for better thermal comfort, and swirling air diffusers are usually used. In order to rigorously simulate the flow characteristics of such diffusers, we used the multi-grid technique and validated it with experimental results. In this paper, the technique is used to compare the square diffuser and the swirling diffuser.
An experiment was carried out to determine the effect of photocatalytic air cleaning on perceivedair quality. Thirty-eight subjects assessed the air quality in a low-polluting, 108 m3 office, with pollution sources either present or absent behind a partition. The pollution sources were carpet, linoleum and chipboard. The office was ventilated with outdoor air at 0.6, 2.5, and 6 h-1. The air temperature was 22C and the relative humidity 40%.
The paper reports on findings from a series of experiments where the supply flow rate wasvaried periodically in time. All experiments were conducted in a small scale model with water as operating fluid. The flow was visualised by adding particles to the water and the streaks were recorded with a digital camera. The main result is that there exist variations that generate a role up of the base flow by generation of vortices that are shed into the stagnant region.
The perceived intensity is investigated by a trained group of 10 to 15 persons. Until now fieldstudies have to be made at the location of interest. All members of a trained group have to visit e.g. a building in order to estimate the perceived intensity of the indoor air. The trained group is influenced by the local environment. This paper presents a new method to sample and to store air probes at arbitrary locations. The air probes can then be transported to the laboratory where a standard group test can be made in the neutral and clean environment of an air quality lab.