Mimicking a Double Skin Roof Experiment

CHAPTER 3 METHODOLOGY OF EXPERIMENT

3.1 Experiment Preparation

There are three main steps in preparing the experiment, which are a) experiment principle & design; b) calibration of resistance temperature detectors (RTDs) and thermocouples (TCs) and c) Set up of equipment.

3.1.1 Experiment Principle and Design

In laboratory experiment, two open-ended parallel plates are used to mimic the double skin roof. For downward heat flow’s case, the upper plate is heated to a constant high temperature, and the lower plate is exposed to indoor environment. The length and width of the parallel plates are .The parallel plates are adjusted to varying the inclinations of ѳ=15º, 30º, 45º and different cavity heights of 3cm, 6cm, 9cm.

After achieving a steady-state in each case, measurements are taken to record the roof surface temperatures, ventilated air flow rate, air temperature at the inlet, in the middle, and at the outlet of the cavity which are illustrated in Figure 3.1.

Figure 3.1: Sketch of the experimental setup

3.1.2 Calibration of Thermocouples and RTDs

The calibration temperatures are 25º, 35º, 45º, 55º and 65ºC (Range of 25ºC to65ºC with the increments of 10ºC). The table below has showed the linearity of recorded temperature with respect to the text probe’s temporary. (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-1

As shown in the above table, the temperature readings are verified by plotting a linear graph for each sensor respectively. The graphs can help to check any errors from the sensors by looking at faulty points which would be plotted beyond the linearity of the graph. If a sensor is consistent in its read...

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...g components for industrial production, PhD. Thesis, Ecole Nationale Superieure des Mines de Pairs, 2000.

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