Heat Transfer in a heat exchanger.

de312

I wanted to try and clarify this. If it is just a double tube simple heat exchanger like this shown here.

http://i56.tinypic.com/34znmti.png

*What is the calculation to calculate the heat transfer coefficient.
*How much surface area would be required between the two pipes for the solution to cool from 150 degrees to 80 degrees.

de312	I wanted to try and clarify this. If it is just a double tube simple heat exchanger like this shown here. http://i56.tinypic.com/34znmti.png What is the calculation to calculate the heat transfer coefficient. How much surface area would be required between the two pipes for the solution to cool from 150 degrees to 80 degrees.