[esp-r] Re: Sky view factor & External insolation

[Sean C Lu]

Hi Jon

many thanks for your useful imformation, I have download the newest version
(11.5), and I can see the result list  for the diffuse shading, I think that
is actually  the so call Sky View Facter , coz it is defined by the
proportion of  How much sky ia able to be seen .

as we know, there are generally 2 methods for calculating  the " diffuse
shading", one is numerical methods to integral the segment of sky dome, the
others way is geometric methods (fish-eye concept with ray-tracing way) to
account the amount of spray ray.  I am just wondering  what kinds of method
Esp-r use here ? any documentation/ reference is available to understand the
code of this calculation?


the 2rd question, under the menu of Model Context , what does the Sky View
Factor mean?
is it the global setting as the average SVF for every surface of the
building geometry? or it's juat a empirical setting ? what is the criteria
for set this value?

the last qustion, again, can esp-r calculate the insolation for the external
face of surface?

thank you very much indeed.

Sean




2008/7/22 Jon Hand <jon at esru.strath.ac.uk>:

>
> A question about shading and about sky view factors.
>
> In the ish module, when the term 'shading' is used it
> actually is shading on the outside face of surfaces facing the
> outside. If there is some place in the documentation and/or
> contextual help that would indicate something else please
> let us know so we can correct this.
>
> And the shading in the newist version can calculate both
> the direct and diffuse shading. The diffuse shading has
> a good idea of how much of the sky is seen from each
> surface.
>
> The sky view factor is set globally in the 'context' menu
> based on the building/sky/ground settings.
>
> Not sure if I know of an application which calculates sky view
> factors direction. Perhaps someone else does.
>
> -Jon Hand
>
> -----Original Message-----
> From: esp-r-bounces at lists.strath.ac.uk on behalf of Sean C Lu
> Sent: Tue 7/22/2008 8:57 PM
> To: esp-r at lists.strath.ac.uk
> Subject: [esp-r]  Sky view factor & External insolation
>
>  Hi
>
> I am thinking to use Esp-r to simulate the solar performace of shading
> device ( for exampe, the shading device integrated with solar collector) .
> one of the task is to calculate the  solar radiation received by the
> surface
> of the external shading device.
>
> there are two questions for the calculation of incident radiation :
>
> 1 can esp-r calculate the insolation for the external face of surface? (The
> shading and insolation program (ish) can only calculate the distribution of
> insolation within ZONE ?)
>
>
> 2 as we know, the Incident Radiation of Surface = Unshaded Fraction
> * Incident Beam Radiation + Sky View Facter * Incident Diffuse Radiation +
> Ground Diffuse Radiation
> to calculate the component of diffuse radiation ( the 2rd term)  , the
> fraction of Sky View Facter must be known, is there any application can
> calculate the SVF? ( it seems that the application of ESPmrt  only
> calculate
> the viewfactors between surfaces within A ZONE)
>
>
> many thanks for your help.
>
> --
> Sean Lu
> 1st floor SRB
> School of the Built Environment
> The university of Nottingham
> NG7 2RD
> [m] 0775 144 5367
> [O] 0115 84 67260
> [e ]laxcl at nottingham.ac.uk
>
> trees Before printing Please think about the environment
>
>
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