[TRNSYS-users] Problem in creating a new wall type

[David Bradley]

The u-value shown in TRNBuild is based on the wall materials but also 
includes an assumed combined heat transfer coefficient to the inside and 
outside surfaces (7.7W/m2.K inside and 25 W/m2.K outside). The value is 
only for display purposes because Type56 calculates the inner and outer 
convection and radiation heat transfer coefficients internally as a 
function of time as the simulation progresses. There is an NTYPE among the 
outputs if you want to know what the actual (time dependent) u-value of the 
wall is.
Kind regards,
  David


At 09:30 3/15/2007, Issa Jaffal wrote:
>Dear All
>When i was trying to make a new wall type in the wall type manager; i
>couldnt explain how the Uvalue in the wall type manager is calculated,
>for istance:
>
>if i make a wall with a single layer of 0.1 m of Concrete  U-value =
>4.595 and if i make a wall with a single layer of 0.2 m of Concrete
>(same layer type)  U-value=3.770 but normaly the U-value will be devided
>by 2 if i double the thikness form 0.1 to 0.2!!!
>
>I tried to change the values of convective heat transfert coefficient
>but  the Uvalue didnt change:
>
>So how we can explain theses values the U-value ?
>
>Regards
>Issa JAFFAL
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>TRNSYS-users mailing list
>TRNSYS-users at engr.wisc.edu
>https://www.cae.wisc.edu/mailman/listinfo/trnsys-users

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