Re: [EnergyPlus_Support] weather file radiation

["Edward Lyon" <eglyon@xxxxxxx>]

The problem with these calculations for energy modeling is that they give you a perfect clear day solar value for any time period you calculate.  If you had additional sky weather data for cloud cover, you could try to apply some cloud cover corrections.  However, correcting the solar data with a cloud cover algorithm is still not as good as measured solar data, it can be as much as 50% off.  I know these cloud algorithms have been applied to some of the canned weather files we use that do not have direct solar measurements, but I have not seen the source equations yet. 

Ned Lyon

Senior Staff Engineer
Simpson Gumpertz & Heger Inc.

41 Seyon Street
Building #1, Suite 500
Waltham, MA  02453

Phone:  781-907-9000
Fax:  781-907-9009


>>> edhugar@xxxxxxxxx 02/06/03 11:28AM >>>



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