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How to define fully opaque shades?

asked 2023-05-18 04:51:27 -0500

Berrak's avatar

updated 2023-05-19 01:19:41 -0500


I modelled two scenarios with fully opaque shades (the first with five facade shades and the second with only one shade at 40 degrees). I expected to have the same cooling energy. But the first scenario in Zone A is 424 kWh, while the second one is 478 kWh. Why are the results different for one shade above another shade? They should be the same. image description

Thanks, Berrak

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@Berrak it looks like your image didn't attach correctly. Can you please try to attach the image again?

Aaron Boranian's avatar Aaron Boranian  ( 2023-05-18 08:34:36 -0500 )edit

Hi @aaron, Thank you for your reply. I have edited the image. I think you can see it now.

Berrak's avatar Berrak  ( 2023-05-19 01:23:49 -0500 )edit

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answered 2023-05-21 16:17:34 -0500

updated 2023-05-21 16:58:28 -0500

Not a definitive answer - yet possibly an answer.

Assuming you're using EnergyPlus (although comparable engines would likely behave similarly), differences in results could come from reduced solar-ground reflections in Scenario 1. Both sky and beam solar contributions, diffusively reflected from the ground towards receiving surfaces, are diminished (vs Scenario 2). You could look into detailed output, or simply tweak the site ground reflectance for a quick assessment.

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Asked: 2023-05-18 04:51:27 -0500

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Last updated: May 21 '23