A 50,000-ft2 condenser is constructed with 1-in.-OD brass tubes that are long and have a 0.049-in. wall thickness. The following thermal resistance data were obtained at various water velocities inside the tubes (Trans. ASME, Vol. 58, p. 672, 1936).
Assuming that the heat transfer coefficient on the steam side is 2000 Btu/h ft2 °F and the mean bulk water temperature is 50°C, determine the scale resistance.