(d) Having seen the performance of the single layer wall, a decision is made to upgrade the wall for this refrigeration
Posted: Tue Apr 26, 2022 3:51 pm
(d) Having seen the performance of the single layer wall, a decision is made to upgrade the wall for this refrigeration store to a composite wall with the construction details shown below, what would be the new overall thermal transmittance. (14 marks]
1.0 Internal convective heat transfer coefficient 5 W/m?.K 2.0 Plastic sheeting. Thickness - 4 mm Conductivity - 1.0 W/mK 3.0 Timber studs. 100 x 50 mm Inside Air Layer Plastic Sheet Timber studs plus Insulation Outside Air Layer Plywood -50 mm Conductivity -0.13 W/mK Inside Outside 4.0 Insulation. Thickness - 100 mm 450 mm Conductivity - 0.03 W/mK -50 mm 5.0 Plywood. Thickness - 12 mm Conductivity -0.13 W/mK 6.0 External convective heat transfer coefficient 10 W/m2.K 450 mm
1.0 Internal convective heat transfer coefficient 5 W/m?.K 2.0 Plastic sheeting. Thickness - 4 mm Conductivity - 1.0 W/mK 3.0 Timber studs. 100 x 50 mm Inside Air Layer Plastic Sheet Timber studs plus Insulation Outside Air Layer Plywood -50 mm Conductivity -0.13 W/mK Inside Outside 4.0 Insulation. Thickness - 100 mm 450 mm Conductivity - 0.03 W/mK -50 mm 5.0 Plywood. Thickness - 12 mm Conductivity -0.13 W/mK 6.0 External convective heat transfer coefficient 10 W/m2.K 450 mm