[esp-r] Re: shading by a semi-transparent obstruction ....... ?

[Achim Geissler]

Hi Gunter,
it will be interesting what others think / know(!). Here is my understanding:
The ESP-r "obstructions" can not be semi-transparent. So, you can either approximate the hundreds of tubes by condensing them into less with the according overall shading area (actually, making them is not quite as large a p-i-t-a as one would initially think ... see attached screen shot). Or, if you want to use something semi-transparent, you will need to build a very well ventilated additional zone (zones) around your model with the appropriate external façade properties (55% transparent). Of course, directional radiation will be lost by ESP-r after going through this external envelope. This approach could, however, take any heating-up of the shading tubes into account. As far as I know, ESP-r "obstructions" do not "warm up".
For what its worth ...
Best regards,
Achim



Mit freundlichen Grüssen / Best regards
 
Achim Geissler
> -----Original Message-----
> From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-
> bounces at lists.strath.ac.uk] On Behalf Of Pueltz, Gunter
> Sent: Thursday, November 02, 2006 1:36 PM
> To: 'esp-r at lists.strath.ac.uk'
> Subject: [esp-r] shading by a semi-transparent obstruction ....... ?
> 
> A question to the ESP shading specialists:
> 
> I have to model a very special type of external shading:
> The complete building shows an "external envelope",
> which consists of parallel metal tubes (see attached figures:
> section and view of this "envelope").
> This external grid of horizontal tubes shows a shading coefficient
> of appr. 45% (55% is free open area). Now my question:
> 
> How to model a semi-transparent (appr. 55% transmission) shading ?
> Does ESP-r calculate the transmission of the incident solar radiation
> through a transparent external obstruction (e.g. a glazing with
> transmission of 55%) in a correct way ?
> 
> If transparent obstruction does not work: Any other idea ?
> I do NOT want to model hundreds of single tubes ........ !!!!
> 
> Regards,
> Gunter
> 
> --
> Gunter Pültz
> 
> Müller-BBM GmbH
> Robert-Koch-Straße 11
> 82152 Planegg
> Telefon +49 (0)89 85602 - 336
> Telefax +49 (0)89 85602 - 111
> http://www.MuellerBBM.de


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