The heat convection coefficient on the outer surface of a 15 cm thick concrete roof (k = 2 W/m℃) of a house with a width of 15 m and a length of 20 m is estimated to be 15 W/m2℃ and the surface dissipation rate is 0.9. The internal surface temperature of the roof is maintained at 15℃. On a clear winter night, the night sky temperature for radiative heat transfer is 255 K while the ambient air is 10℃. Calculate the temperature of the outer surface and the total heat transfer through the roof, taking into account both radiation and convection heat transfer?