Q3 For a university building, steam at 150°C for heating is supplied from a remote boiler house through a 35m length of insulated pipe over the road at first floor level.

The pipe has an inside diameter of 0.15m with a wall thickness of 10mm and conductivity of 48 W/(m.K). The insulation is 50 mm thick with a conductivity of 0.87 W/(m.K). (a) State Fourier's law of conduction for an infinitely long cylinder and define the terminology used. [5/20 marks] (b) Calculate the heat loss when the atmospheric temperature is -5°C and the heat transfer coefficients between the steam and pipe and from the insulation to the atmosphere are 2.84 and 34.1 kW/(m2.K) respectively [15/20 marks]