[BLDG-SIM] Fraction of Possible Sunshine

Jon McHugh mchugh at h-m-g.com
Wed Sep 26 11:00:42 PDT 2001


Jon,
 
SkyCalc is simple to use tool to look at daylighting potential from
skylights and daylight harvesting controls potentials.  SkyCalc is an Excel
spreadsheet that uses preprocessed DOE-2 hourly outputs to generate energy
savings estimates for different fractions of roof area covered with
skylights and under different lighting control strategies.
 
SkyCalc is free and is available with climate specific "weather files" for
34 locations.  SkyCalc can be downloaded from www.h-m-g.com
<http://www.h-m-g.com> .
 
Jon McHugh, PE, LC 
Heschong Mahone Group 
11626 Fair Oaks Blvd #302 
Fair Oaks, CA 95628 (Sacramento) 
(916)962-7001 
(916)962-0101 FAX 
e-mail: mchugh at h-m-g.com 
URL: www.h-m-g.com 

-----Original Message-----
From: Jon Maxwell [mailto:jmaxwell at aspensys.com]
Sent: Wednesday, September 26, 2001 8:55 AM
To: BLDG-SIM at gard.com
Cc: BLDG-SIM at GARD.COM
Subject: [BLDG-SIM] Fraction of Possible Sunshine


I wanted to compare FPS plots against radiation plots so I could learn more
about their correlation (or lack thereof) in different locales.  I planned
to use one or the other to help me get a sense for possible regional
variation in daylighting/dimming controls savings potential.  I had a lot
easier time finding radiation data, if it is any consolation to you in your
mission, Chip. but I thought sunshine data would be better to use if
available.  Tabular data is better for quantitative analysis of course, but
I wanted to see pictures.
 
FYI two good sources for solar radiation plots are: 
 
    -   <http://www.homepower.com/solmap.htm>
http://www.homepower.com/solmap.htm 
       for an annual plot (attractive training illustration),
 
    -   http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/Table.html
<http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/Table.html>  
       for monthly plots by various orientations ( a better analytical
tool).
 
Not to be too contrary but I spot-checked the tabular data from the source
in my original email with the homepower map above and the general patterns
do seem to correlate pretty well. 
 
Finally, for those of you that are interested, Jeff Haberl responded to me
directly with a FPS resource: "I believe that there is a map on Kreith and
Kreider's Solar energy handbook...that shows this for the world...using the
Angstrom-Lof minutes of sunshine."  Thanks to Jeff.
 
 
----- Original Message ----- 
From: Chip  <mailto:cbarnaby at wrightsoft.com> Barnaby 
To: Jon Maxwell <mailto:jmaxwell at aspensys.com>  
Cc: BLDG-SIM at GARD.COM <mailto:BLDG-SIM at GARD.COM>  
Sent: Wednesday, September 26, 2001 9:12 AM
Subject: Re: [BLDG-SIM] Fraction of Possible Sunshine


Jon --

I don't know of a source for a map, but I do have a question ... what do you
want it for?

I am trying to learn how people use this statistic.  It has been
traditionally observed, so people keep observing it.  I am involved in work
on ASHRAE TC 4.2 (Weather Information) that is developing methods for
extracting solar radiation from weather data measured by ASOS (Automated
Surface Observation System) now used to observe weather at most sites in the
US.  ASOS has planned to add sunshine meters to their machines (that plan is
now delayed due to funding), but it would be just about as easy, and much
more useful (in our opinion) to measure solar radiation.  Sunshine fraction
is a notoriously bad predictor of solar radiation (the correlations are
pretty poor).  With trivial data processing, minute-by-minute solar
radiation data can be used to estimate sunshine, but not vice-versa.

Thus as far as I know the solar and building simulation community has no use
for sunshine data -- the statistic should be declared obsolete from our
point of view.  However, at every opportunity, I try to find why people want
it, there may be some other uses that we don't know about.

So, if you're willing, please let me know what you're up to.

To the rest of BLDG-SIM: anyone else know of uses for sunshine fraction?

Thanks, Chip Barnaby



Does anyone out there have or know of a source for a graphical illustration
of Fraction of Possible Sunshine over the U.S.  I found a very good table of
such data at http://cdiac.esd.ornl.gov/ftp/ndp021/
<http://cdiac.esd.ornl.gov/ftp/ndp021/>  (file #12), but haven't had any
luck with a map.  Thanks in advance.
 
Jon Maxwell, PE
Aspen Systems Corp.
jmaxwell at aspensys.com <mailto:jmaxwell at aspensys.com>  
 
 




You received this e-mail because you are subscribed 

to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 

from this mailing list send a blank message to 

BLDG-SIM-UNSUBSCRIBE at GARD.COM


---------------------------------------------------------
Chip Barnaby                   cbarnaby at wrightsoft.com
Vice President of Research
Wrightsoft Corp.               781-862-8719 x118 voice
394 Lowell St, Suite 12        781-861-2058 fax
Lexington, MA 02420            www <http://www.wrightsoft.com/> .wrightsoft.
com <http://www.wrightsoft.com/> 
--------------------------------------------------------- 



=====================================================You received this
e-mail because you are subscribed 

to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 

from this mailing list send a blank message to 

BLDG-SIM-UNSUBSCRIBE at GARD.COM



======================================================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20010926/eca5523e/attachment-0002.htm>


More information about the Bldg-sim mailing list