CHAPTER 3 EXPERIMENT METHODOLOGY3.1 Experiment PreparationThere are three main steps in experiment preparation, which are a) experiment principle and design; b) calibration of resistance temperature detectors (RTDs) and thermocouples (TCs) and c) Equipment setup.3.1.1 Experiment principle and design In the laboratory experiment, two open parallel plates are used to imitate the roof double skin. In the case of downward heat flow, the upper plate is heated to a constant high temperature and the lower plate is exposed to the internal environment. The length and width of the parallel plates are .The parallel plates are adjusted to vary the inclinations of ѳ=15º, 30º, 45º and different cavity heights of 3cm, 6cm, 9cm. After reaching a steady state in each case, measurements are taken to record the roof surface temperatures, ventilated air flow rate, air temperature at the inlet, center and outlet of the cavity, illustrated in Figure 3.1. Figure 3.1: Sketch of the experimental setup 3.1.2 Calibration of thermocouples and RTDThe calibration temperatures are 25º, 35º, 45º, 55º and 65ºC (range 25ºC to 65ºC in 10ºC increments). The following table showed the linearity of the recorded temperature compared to the temporary temperature of the testo probe. (Appendix 1) Table 3.1.1: Calibration of RTD-B1 Figure 3.2.1: Graph of RTD-B1 Table 3.2.1: Calibration of TC-1 Figure 3.2.2: Graph of TC-1A As shown in the table above, Temperature readings are verified by plotting a linear graph for each sensor respectively. Graphs can help check for sensor errors by looking at bad points that would plot beyond the linearity of the graph. If a sensor is consistent in its reading...... middle of paper ......g components for industrial manufacturing, PhD. Thesis, Ecole Nationale Superieure des Mines de Pairs, 2000.[6]. CSTB, Determination of the thermal performance of a roof ventilation system(in French), E-01-0005, Grenoble,2002.[7]. http://arxiv.org/ftp/arxiv/papers/1312/1312.1295.pdf.[8]. P.-C. CHANG et al., Development and preliminary evaluation of flysheet prototypes incorporating RBS (radiant barrier system), Energy & Building (2007).[9]. J. Hirunlabh, W. Kongdang, P. Namprakai, J. Khedari, Study on natural ventilation of houses using metallic solar walls in tropical climate, Renewable Energy 18 (1).[10].[11]. XQ Zhai, YJ Dai, RZ Wang, Experimental investigation of air heating and natural ventilation of rooftop solar collector.[12]. http://www.greenspec.co.uk/whole-house-ventilation.php.[13]. http://weatherspark.com/averages/34047/Singapore.