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LightLouver never showing savings

asked 2017-05-02 15:31:05 -0600

Determinant gravatar image

updated 2017-08-06 07:42:34 -0600

I can’t get LightLouver to show savings over a clerestory of equal size. I’ve tried upping the ambient parameters, increasing the height of the clerestory that they’re mounted on, and just finished some runs with a larger illuminance map to try to find a better sensor location. No luck in any case. Illuminance levels are always higher in the clerestory case for (practically) all hours and all grid points on the illuminance map.

I’d really appreciate any help. I’ve place my most recent files here:

https://www.dropbox.com/s/qml2km7b4f3...

https://www.dropbox.com/s/bxlykuss694...

I'm using the regular OS/Radiance measure without any of my mods for those who know I'm working on mods.

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Without looking at your model (because I don't have time and am still on leave), there are a couple of possible causes for this:

  1. The window head height to room depth is very low
  2. You don't have any other shading or diffusion on the clerestory for the non-LL design
rpg777 gravatar imagerpg777 ( 2017-05-03 09:20:44 -0600 )edit

Clerestory head height is 10', room is 30' deep. I'm looking at illuminance from 5-20' deep. I don't have any shading for the runs I posted, but do have other runs with shading. LL shows some very small savings over clerestory-only if the clerestory-only case has shades for both view and clerestory versus an LL run that only has shades at the view window. Didn't know you were still on leave! Rest up! But anyone else who can chime in is super-appreciated.

Determinant gravatar imageDeterminant ( 2017-05-03 11:56:46 -0600 )edit

Instinctively it wouldn't surprise me if the LL impact in a 10ft high and 30ft deep room is primarily to mitigate some of the effects from window shade use (like a full-year moderation of lighting levels from the extremes with full-height shade use). Although - I haven't actually checked your model, so can't say if there's any errors or other issues to be corrected. Can you dive into the results data to see if the annual trends make sense? What if you compare the LL to a clerestory with light shelf? Or to a full-height shade that's not split between view/clerestory?

Chris Rush gravatar imageChris Rush ( 2017-05-09 10:59:31 -0600 )edit

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answered 2017-11-04 16:01:47 -0600

Determinant gravatar image

I set a higher VT for the LightLouver case and also changed the orientation of my glare sensor (both cases) to be more affected by the clerestory direct beam glare. I also gave a better "furniture factor" for LightLouver in post-Radiance number crunching.

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Asked: 2017-05-02 15:31:05 -0600

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Last updated: Nov 04 '17