Ans: 1. Using the laws of thermodynamics the amount of heat transfer is calculated but the rate of heat transfer (how long the process will take place) is known using principles and laws used in heat transfer.

2. Thermodynamics deals with equilibrium states, whereas heat transfer deals with non-equilibrium states.

3. Thermodynamics is used for calculating mass flow rate in different parts of the system.

4. Heat transfer is used in sizing the systems (or calculating surface area in other words)

5. Heat transfer is used for calculating the heat transfer coefficient, h.