Thermal conductance

[Sinexus]

I'm determining the overall u-value accross a wall section. In the formula for doing this there is an "alpha". One for the outside and one for the inside. It is the thermal conductance, W/m2*K. Determining the value of this tends to be difficul since it depends on air speed, temp etc, so I was hoping someone in here had a few tips on how to find it. Anything will be appreciated!

 

[25362]

I assume you are after heat transfer coefficients. If so visiting the following threads may bring you some help:

thread391-87136
thread391-98626
thread391-102097

Good luck.

 

[IRstuff]

If you don't know "air speed, temp," how do you expect anyone else to know about your specific design conditions?

TTFN

 

[Sinexus]

I know all of these, but I don't have an equation in which to put them and stir them all into a single number.

 

[epoisses]

Unfortunately the equation to be used depends on the conditions (regime)!

 

[IRstuff]

There are plenty of heat transfer engineering websites with those equations posted:

http://www.onesmartclick.com/engineering/heat-transfer.html

TTFN