=+8-20.

The attic space shown in Fig. 8-11 has H = 3 m. W= 12 m. and Z = 18 m, and all interior sur-

faces have emissivities of 0.9. For a time when the inside surface temperatures are ", = 43 C.

12 = 50 C. f3 = 36 C, t = 38 C, and t = 32 C, estimate the net thermal radiation incident on each surface using the MRT/balance method.