[Bldg-sim] Errors in TMY3 Files

[Linda Lawrie]

the TMY3 files on climate.onebuilding.org have been corrected from 
the document posted by Joe Huang on the tmy3 site.  But I think that 
was for precipitation.

the TMYx files would never have had this problem as they come from a 
different source of our creation for the TMYx files.

And, as I remember, the illuminance problem was corrected by NREL at 
some point after their first post.

------
Linda

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>Does anyone know if the errors described in TMY3 files in this post 
>from Joe Huang on Jan 14 2015 still exist in files on the 
><http://climate.onebuilding.org/>http://climate.onebuilding.org/ 
>website? And were these errors also fixed in TMYx files?
>
>Specifically I'm interested in this issue:
>
>
>1) Illuminance. The TMY3s contain values for Global Horizontal, 
>Direct Normal, Diffuse
>Horizontal, and Zenith Illuminance that are calculated based on the 
>sun position and solar
>radiation. Although the documentation states that the units are 100 
>lux for the first
>three illuminances, and 10 candela/m2 for the Zenith Illuminance, 
>all the TMY3 files used
>these units only for the period Jan. 2-31, and for the rest of the 
>year used units of lux
>and candela/m2, respectively. NREL put out a notice in August 2008 
>(see the link listed
>earlier) informing users of this discrepancy and promising a 
>corrected version that didn't
>make it out until now! In this revision, we've decided to keep the 
>units in the original
>TMY3 documentation, i.e., 100 lux or 10 candela/m2, which is the 
>same as what was in the
>TMY2, and avoids the superfluous five-digit precision.
>
>If I use a TMY3 or TMYx file from the climate.onebuilding.org 
>website, am I getting a TMY3 or TMYx version in which these issues 
>are corrected?
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