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Q2 As a building engineer, you are required to design of building's wall to be comply with a recommended thermal transmittance value (U-value) between 2.5 to 2.6 W/m²K. The wall's construction consists of brick with plaster on both sides. Table 2 shows the materials thermal conductivity and the surface resistance of the wall. (i) Based on the information given, propose the required thickness of the wall layers to achieve the recommended requirements. (8 marks) (ii) If the mass insulation needs to be added to the wall in order to reduce the thermal transmittance of the wall to be within 1.0-1.2 W/m²K, determine the required thickness for the insulation. Given, the thermal conductivity for the insulation is 0.04 W/mK. (4 marks)
Table 2: Material properties of wall Material Brick Plaster External surface resistance Internal surface resistance Thermal conductivity (W/mK) Thermal resistance (m²K/W) 0.807 0.57 0.044 0.16