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Report A3132.1 <br /> Page 14 <br /> Table 3.- Change in Thermal Performance – Yearl and Year 2 Relative to <br /> Start <br /> S ecimen Position 2 3 4 <br /> Yearl 5 Avera e <br /> Systeml (West) 1.2% 0% -3.4%* <br /> S stem 2 East 2.9% 1.3% -0.2% <br /> Avera 0% --- 8.0% 3.6% <br /> Year2 a 2.1% 0% -3.4% 4.6% 1.4% <br /> Systeml (West) 6.0% <br /> S stem 2 Imimon <br /> Avera e 4.5% 2 9% - <br /> ' Modified sum pp 2.2% 10.4% 5.4% <br /> p pump controls appear to have affected this specimen in the first year. <br /> Assessment of 3-Dimensional Heat Flow <br /> Over the course of the 2-dimensional analysis, it was noted that the temperature of the <br /> concrete (behind the specimens) differed from specimen to specimen. This raised <br /> Possibility that heat could flow through the concrete from one specimen to another, the <br /> resulting in possible uncertainty in the orders of magnitude of performance assessed <br /> using the 2-dimensional analysis. <br /> In response to this, a detailed 3-dimensional heat transfer analysis_ of the both the east <br /> wall and the west wall was undertaken. The same control volume depicted in Figure 14 <br /> was used for the 3-D analysis, but this Was extended in the third dimension along the <br /> wall, to encompass all specimens. The objective of this much more detailed analysis <br /> was to determine the order of magnitude of lateral heat flow in the concrete from one <br /> specimen to another, and to provide a correction on the 2-dimensional results for in-situ <br /> R-value of each specimen, where needed. <br /> To illustrate the result of this analysis, an example result is shown in Figure 16 for the <br /> west wall. The angle between the actual heat flux vector and the normal direction is <br /> defined here as the heat flux angle; e.g, a zero angle denotes heat flux normal to the <br /> wall —no lateral heat flow. The heat flow angle is plotted for the 'top' location (top of <br /> the control volume) in the concrete, at one point in time. A positive angle means lateral <br /> heat flow towards one end of the wall, and a negative heafflow means lateral heat flow <br /> towards the other. <br /> The significance of this diagram is as follows. If the flow angle in the concrete behind <br /> the specimen is small, and in the same direction, then the lateral heat flow has little <br /> effect on the results. This was the case for W2, W3, W4, W5, the EPS specimens <br /> The 3-D analysis thus confirmed the order of magnitude of performance analyzed usin <br /> the 2-6 method for the EPS specimens. g <br />