How to calculate energy saved in HVAC Duct?

[jmarkus]

I have two different materials for air ducts. If I have cool air flowing through the first duct, the temperature difference between the inlet and outlet of the duct is 3 degrees C. For the second duct it is 5 degrees C. The first duct is obviously a better insulator, but how do I quantify how much energy is saved from the first duct compared to the second duct?

Thanks,
Jeff

 

[btrueblood]

mass flow rate x specific heat x temperature difference

 

[MintJulep]

Or simpler yet:

1.07 x cfm x temperature difference

 

[jmarkus]

What units does that give me (the 1.07 x cfm x delta T)?

 

[willard3]

This sounds like homework to me.........

 

[jmarkus]

It isn't homework, it's trying to help a structural design engineer remember thermodynamics and heat transfer which has escaped me.

Thanks for your help.

 

[MintJulep]

What units does that give me (the 1.07 x cfm x delta T)?
BTU/hr