=+5-34.

Estimate the beat loss from 100 m of buried hot-water pipe. The mean water temperature is 60 C. The copper pipe with 20 mm of insulation, k = 0.05 W/(m-C), is buried 1 m below the surface and is 50 mm in diameter. Assume a thermal conductivity of the earth of 1.4 W/(m-C)

and a ground surface temperature of 5 C.