Re: [TRNSYS-users] Transfer function

["Eleni Ampatzi" <ampatzie@Cardiff.ac.uk>]

Julien,

When you assign a massless material the software ignores the thermal mass effect. 

For the solar absorptance, two values are used by the software for the FRONT and the BACK of it.
Save your wall in the user library and then select LIBRARY from the WALL TYPE pull-down menu within
the ZONE window. The wall library window opens and if you click on your element you will be able to
amend its solar absorptance. To choose appropriate values check page 28 in the Multizone Manual as
the solar absorptance coefficient depends on the finish of the material. 

I hope I am not wrong, as I am not very confident with TRNBuild yet. Please someone corrects me if
that is the case!

Hope I helped you with this.

Best Regards

Eleni

>>> "Julien L'Hoest" <julien.lhoest@gmail.com> 08/05/08 2:54 PM >>>
Ok I assigned a massless material and it works. Increasing the timebase
didn't work.

Do massless materials absorb solar irradiation like massive materials ?

Regards,

Julien.

2008/5/8 Eleni Ampatzi <ampatzie@cardiff.ac.uk>:

> Dear Julien,
>
> You can modify the timebase in TRNBUILD, through the 'PROJECT' main window
> and by clicking
> 'OUTPUTS'.
>
> Sometimes you might need to assign a massless material to solve similar
> problems.
>
>
> Best Regards
>
> Eleni Ampatzi
> WSA Cardiff University
>
> >>> "Julien L'Hoest" <julien.lhoest@gmail.com> 08/05/08 12:54 PM >>>
> Dear all,
>
> I had this message with type 56 :
>
> UNABLE TO FIND A ROOT AFTER INDICATION THAT A ROOT EXISTED
>
>  CHECK THE WALL TYPE AFTER THE LAST CALCULATED WALL
>  OFTEN THE WALL CAPACITY IS TO SMALL TO CALCULATE A TRANSFER FUNCTION !
>
>  CHECK ALSO YOUR TIMEBASE !
>
> Is it possible to modify the timebase  ? I'm trying to model a thin roof.
>
> Regards,
>
> Julien L'Hoest.
>
>