Consider the wall section shown in Fig. P4 which consists of gypsum layer (RG = 0.08 m.C/W), insulation (Rins = 1.94 m.C/W), sheathing (Rs = 0.18 m.C/W), and brick wall (RB = 0.14 m.C/W). (a) Compute the temperatures of surfaces 1 and 2; (b) Assuming that the moist air can diffuse through the gypsum and insulation from the inside, would you expect moisture to condense on surface 1? Explain. (c) Would moisture condense on surface 2? Explain; and (d) Where should a vapor retardant be placed? Assume the indoor and outdoor humidity ratios are approximately equal. T = 21C To = -12C $ = 90% Air film, R,= 0.03 Brick, RB 0.14 Sheathing, R.= 0.18 Insulation, Rins = 1.94 Gypsum, RG = 0.08 Fig. P.4