[Radiance-general] modeling hourly daylight illuminance/daylight factor values for a year

[John Mardaljevic]

Ramana,

A brute-force approach (i.e. a new simulation for every hour) can be  
done, but it is computationally very inefficient.  A better approach  
is to use daylight coefficients.  Background, theory and  
implementation are described in chapter 6 here:
http://www.iesd.dmu.ac.uk/~jm/zxcv-thesis/
[Web pages seem to be down at the moment - try again later/tomorrow]

An end-user DC version called DAYSIM is available from here:
http://irc.nrc-cnrc.gc.ca/ie/lighting/daylight/daysim_e.html
DAYSIM is different in detail from the description noted above, but  
does more or less the same thing.

-John

-----------------------------------------------
Dr. John Mardaljevic
Senior Research Fellow
Institute of Energy and Sustainable Development
De Montfort University
The Gateway
Leicester
LE1 9BH, UK
+44 (0) 116 257 7972
+44 (0) 116 257 7981 (fax)

jm at dmu.ac.uk
http://www.iesd.dmu.ac.uk/~jm