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
-----------------------------------------------
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:[email protected]]
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
-----------------------------------------------
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:[email protected]]
*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
-----------------------------------------------
If you are using a shadow ring to get the diffuse horizontal irradiance you
have to adjust the sliding bar manually around 1 or two times a week
regarding to the documentation. below you will find the link to the Manual
for the shadow ring of Kipp & Zonen.
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:[email protected]]
*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
-----------------------------------------------
I can confirm, that the delta-T sensor delivers very good and accurate values. Problematic is just sun-rise and sun-set.
In case you have only the global horizontal iilluminance, the Erbs model is the most accurate one (but still the error could be huge). This model is implemented in the current version of gendaylit (-E option). you could also see the error and spread of the data in our presentation at the last radiance workshop: http://www.radiance-online.org/community/workshops/2013-golden-co/sprenger_wienold_gendaylit.pdf
If you can afford the sensor, I would go for the delta-T. We used it in several projects and also did comparisons with a tracking pyrheliometer.
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:[email protected]]
*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
-----------------------------------------------
--
Dr.-Ing. Jan Wienold
Head of Team Passive Systems and Daylighting
Fraunhofer-Institut f�r Solare Energiesysteme
Thermal Systems and Buildings
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133 [email protected]
In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30
-----------------------------------------------
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
-----------------------------------------------
On Thu, Apr 10, 2014 at 5:46 AM, Jan Wienold <[email protected]>wrote:
Hi Kyle,
I can confirm, that the delta-T sensor delivers very good and accurate
values. Problematic is just sun-rise and sun-set.
In case you have only the global horizontal iilluminance, the Erbs model
is the most accurate one (but still the error could be huge). This model is
implemented in the current version of gendaylit (-E option). you could also
see the error and spread of the data in our presentation at the last
radiance workshop: http://www.radiance-online.org/community/workshops/2013-
golden-co/sprenger_wienold_gendaylit.pdf
If you can afford the sensor, I would go for the delta-T. We used it in
several projects and also did comparisons with a tracking pyrheliometer.
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:[email protected]]
*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
-----------------------------------------------
--
Dr.-Ing. Jan Wienold
Head of Team Passive Systems and Daylighting
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133 [email protected] http://www.ise.fraunhofer.de
In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30
For delta-T, which one would you recommend? SPN1 or BF5? I find that their main difference is the spectrum range. One is 400-700nm, while the other is 400 - 2700nm. If it is for daylight simulation, it seems that BF5 is enough. But, if I want to put the data together to form an epw weather file for future potential thermal simulation, is it better to use SPN1?
Sorry I cannot tell - At Fraunhofer ISE we had the SPN1 and the comparison with Kipp and Zonen sensors mounted on trackers showed high accuracy. But main application was for PV not daylight.
No experience with the other sensor you mentioned.
Cheers