[Bldg-sim] "Qualified" energy modeling tools for LEED NC v2.2

[Zhai Chaoqin]

David,

I am not familiar with TRNBuild. Does it have a built-in CAD interface that
one can draw a building? Can one define building surfaces by coordinates?
Can one import a 2-D or 3-D CAD drawing? As I recall in Type56, one needs to
pre-calculate the wall and window areas by orientation for each zone and
input the area value into TRNSYS. I am not sure if this is still the case.

Thanks,
Chaoqin


On Fri, Aug 1, 2008 at 9:43 AM, David Bradley <bradley at tess-inc.com> wrote:

> Chaoqin,
>  There are three parts to the geometry issue.
>
>  For internal radiation exchange, you are correct that TRNSYS is a
> non-geometrical model and that two surfaces do not have any knowledge of
> their mutual view factor. Like many of the other building models out
> there, TRNSYS uses a star-network in which each surface "radiates" to
> the air node and vice versa.
>
>  For external geometry, one defines orientations in the building
> processor (TRNBuild) and then defines corresponding surfaces (slope and
> azimuth) in the weather data reader. Solar radiation from a particular
> weather data reader surface is then linked to the appropriate Type56
> inputs for each orientation defined in TRNBuild.
>
>  For external shading (including building self-shading), one places a
> series of wingwall and overhang components between the unshaded solar
> radiation calculated by the weather data reader and the building, in
> effect cutting down on the amount of radiation incident on the building.
> It is a flexible methodology but a bit of a cumbersome one. One of the
> main pushes in the current development of TRNSYS 17 is a much more
> automated methodology for doing building self-shading. The Type56
> developers are also working on a true view-factor methodology for
> internal radiation exchange within a zone.
>
> Kind regards,
>  David
>
> **************************************
> David BRADLEY - Principal
> Thermal Energy System Specialists, LLC
> 2916 Marketplace Drive - suite 104
> Madison, WI  53719
> USA
>
> Ph: +1.608.274.2577
> Fx: +1.608.278.1475
> bradley at tess-inc.com
> http://www.tess-inc.com
> http://www.trnsys.com
> **************************************
>
>
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