Heat and Mass Transfer

A walk-in deep freezer wall is made of 120 mm thick brick layer on the outside followed by 75 mm thick concrete and 50 mm thick cork layers inside. The mean temperatures measured over inside and outside wall surfaces are −18 °C and 24 °C, respectively. The thermal conductivity of brick, concrete and cork are 0.69, 0.76 and 0.043 W m⁻¹ K⁻¹, respectively. Considering one square meter wall surface area, the heat transfer rate in W is ____________. [round off to one decimal place]