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Total/Opaque Sky Cover (tenths) vs Cloudiness (octa)

asked 2021-04-19 04:54:29 -0500

updated 2021-04-19 08:36:31 -0500

Hi everyone,

In my actual weather data, I don't have Horizontal Infrared Radiation Intensity but cloudiness, whose unit is octa (i.e. 1 is 1/8). From Energyplus documentation, I saw that the Horizontal Infrared Radiation Intensity can be calculated from the Opaque Sky Cover, whose unit is tenths (i.e. 1 is 1/10 covered, 10 is total coverage). Could someone tell me please if the cloudiness in actual weather data corresponds to the Opaque Skey Cover in EPW. If yes, Do I have to convert octa into tenth for the calculation of Horizontal Infrared Radiation Intensity?

Thank you very much for your help.

L. Lê

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answered 2021-04-19 09:31:04 -0500

lklawrie's avatar

If the units are given as octas, then the cloudiness could be considered equivalent to sky cover after multiplying by 1.25.

With a proper definitions file, the Energyplus Weather Converter can also do that for you.


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Thank you very much for your answer.

vlle's avatar vlle  ( 2021-04-20 07:48:51 -0500 )edit

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Asked: 2021-04-19 04:54:29 -0500

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Last updated: Apr 19 '21