info on exterior insulation/filling material, etc.-1999

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Report A3132.1 Page 12 that includes optimization routines. This method was documented and applied for determining the in-situ thermal resistance of roof insulations (Gomberg and Kumaran, 1994) 2-Dimensional Analysis The analysis technique for EIBS study was adapted to account for two significant differences in the test set-up: 1. The 200 mm concrete wall was interposed between the reference insulation layer and the test specimen. Analysis showed that the concrete layer modifies the heat flux leaving the reference specimen through heat storage and through heat flow up and along the concrete wall. 2; Temperatures in the soil did not vary significantly on a diumal basis, so that a statistically valid relationship between specimen conductivity and temperature was not needed to the-extent considered for the roofing specimens. The analysis was therefore adapted to assess the heat storage effects and two dimensional heat loss through and up the wall. A second, more elaborate method was developed to assess the heat loss in the third dimension, along the wall, and to suggest what corrections to the 2-D results would be needed. The 2-D analysis consisted of calculating the horizontal heat flux (inside to outside) and vertical heat flux (boftom to top) through all materialsinthe control volume defined in Figure 13. A finite difference technique was used to solve the heat transfer equations for dynamic heat flow through solids with known boundary conditions, at each point of a nodal network used to represent the materials in the control volume (see Figure 14). Using this analysis technique, the temperature differences across the specimen and the concrete were calculated for each measurement interval. The temperature difference across the reference insulation determines the heat flux into the concrete. Finite difference analysis was used to assess the direction and magnitude of heat flux in the concrete as well as the amount of heat stored or released by the concrete. After these quantities are evaluated through the concrete, the resulting net heat flux into the specimen was assessed. Using this heat flux and a postulated thermal conductivity of the specimen, the resultant temperature differences across the specimen were calculated. The calculated temperature differences are then compared to measured results, every ten minutes. Mean errors were calculated on a weekly basis. An iterative technique was devised to minimize the mean error between calculated temperature differences and measured, by adjusting the postulated conductivity of the insulated specimen on a weekly basis. The factor by which the conductivity was adjusted relative to lab-determine conductivities of the specimens was labelled 'conductivity adjustment factor'. These were recorded and plotted on a weekly basis. As well as the reciprocal—the thermal resistance adjustment factors was plotted. As a final step in the analysis process, the