Question

Why convective heat-transfer coefficient(h) of condensing water vapor is higher than that of boiling water?

Answer 1

Answer: Convective heat transfer co-effcient depends upon physiochemical properties of fluid i.e.specific heat, viscosity, densiity and thermal conductivity etc..

Specific heat is directly propotional to heat transfer co-effiicient and is being defined as the amount of heat required to raise the unit degree celsius of an unit mass and specific heat of water vapor is 1.996 kJ/kgK and specific heat of boiling water is 4.187 kJ/kgK. Hence, water vapor will have more rate of heat transfer rate as compared to that of boiling water. Thus, heat transfer coefficient of vapor is more than that of boiling water.