[Radiance-general] Experience implementing gendaylit with physical inputs (-G: direct - horizontal irradiance and diffuse - horizontal irradiance)

[Axel Jacobs]

Hi Kyle,

check out the SPN1 and BF5 from Delta-T:

http://www.delta-t.co.uk/product-category.asp?div=Meteorology%20and%20Solar

Very neat, but I have not used them myself.

If you prefer to use two instruments and shading ring instead, you'll 
need to correct for the shading ring:

Rawlins F, Readings CJ (1986) The shade ring correction for measurements 
of diffuse irradiance under clear skies. Solar Energy 37:407–416

Steven MD, Unsworth MH (1980) Shade-ring corrections for pyranometer 
measurements of diffuse solar radiation from cloudless skies. Quart J 
Royal Meteorol Soc 106:865–872

Painter HE (1981) The shade ring correction factor for diffuse 
irradiance measurements. Solar Energy 26:361–363

Regards

Axel

On 10/04/14 01:29, Christoph Reinhart wrote:
> Hi Kyle,
>
> Your approach is valid. Depending on what your plan to do with the data,
> you can also use just global horizontal irradiance and use the Reindl
> (or another separation model) to model direct and diffuse components. I
> have used Reindl extensively in the past with satisfactory results. For
> validation work using two sensors is of course preferable. You can use
> the gen_reindl.exe command in Daysim to convert a time series of
>
> month day hour global-irradiance
>
> into a Daysim weather file.
>
> Best,
>
> Christoph
>
> *From:*Kyle Konis [mailto:kskonis at gmail.com]
> *Sent:* Wednesday, April 9, 2014 8:08 PM
> *To:* Radiance general discussion
> *Subject:* [Radiance-general] Experience implementing gendaylit with
> physical inputs (-G: direct - horizontal irradiance and diffuse -
> horizontal irradiance)
>
> I am curious if anyone has experience to share regarding the generation
> of skies with gendaylit using physical sensor data as input.
>
> I would like to monitor sky conditions at a building rooftop site and
> plan to collect direct - horizontal irradiance and diffuse - horizontal
> irradiance using Licor pyranometers.
>
> Both sensors will be oriented horizontally. The first will be unshaded
> and record global horizontal irradiance.
>
> The second will have a shadow band applied and will serve to record
> diffuse horizontal irradiance.
>
> I will then subtract the diffuse-horizontal contribution from the global
> horizontal value to obtain an estimate of direct-horizontal irradiance.
>
> I wanted to confirm that this is an appropriate approach, as well as to
> see if anyone has an alternative (better) idea, that does not involve a
> pyrheliometer.
>
> Best,
>
> -Kyle
>
> -----------------------------------------------
>
> Kyle Konis, AIA, Ph.D
> Assistant Professor
> School of Architecture, WAH 204
> University of Southern California
> Los Angeles, CA 90089-0291
> http://arch.usc.edu/faculty/kkonis
> -----------------------------------------------
>
>
>
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