[TRNSYS-users] Internal glazing specification
jeannieboef
jeannieboef at gmail.com
Mon Jul 2 11:03:11 PDT 2012
I believe that the calculation are according to European Norms.
Something like DIN EN 674 (CEN) and 416.
Sent from my iPhone
On 02.07.2012, at 17:20, "Antoine Gautier"
<antoine.gautier at solamen.fr> wrote:
> Dear users
>
>
>
> I am really puzzled by Werner’s post hereunder.
>
> http://sel.me.wisc.edu/trnsys/mailinglist/archive2003/msg00297.html
>
>
>
> If I understand it well, characteristics for internal glazing
> systems should be specified regarding external glazing systems
> characteristics. For instance internal transmittance should be
> different than normalized value if spectrally selective transmission
> is performed by external glazing systems. The reason invoked being
> that the same wavelength cannot be absorbed twice.
>
> However when I think about it, I rather understand transmission
> coefficient (thermal or visible) as a probability of transmission
> averaged on a wavelength interval. Therefore I would intuitively
> conclude that each glazing system transmits radiation as expected
> regarding its normalized characteristics.
>
> When I simulate a fictive 2 * double glazing system in WINDOW with a
> very wide middle air gap I get the following results.
>
> SHGC
> Tvis
>
> Initial double glazing 0.54 0.78
>
> 2*double glazing simulated 0.41 0.62
>
> Characteristics of initial glazing**2 0.29 0.61
>
>
>
> So Tvis resulting from WINDOW calculation is close to the square of
> initial Tvis value but SHGC is in-between.
>
> I would need help to conclude. How should internal glazing systems
> be specified in Trnbuild?
>
>
>
> Also if Radiance users are amongst you I would be very interested to
> know how they handle this issue when specifying transmissivity
> values for internal glass materials.
>
>
> Best regards
>
> --
>
> Antoine Gautier
> Solamen SAS
> +33 6 58 24 02 60
>
> antoine.gautier at solamen.fr
>
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20120702/d8447a53/attachment-0001.htm>
More information about the TRNSYS-users
mailing list