# Radiance simulations maintain 200	lux minimum

**URL:** <https://discourse.radiance-online.org/t/radiance-simulations-maintain-200-lux-minimum/2154>\
**Category:** radiance-general\
**Created:** [April 20, 2004, 2:45pm UTC](https://discourse.radiance-online.org/t/radiance-simulations-maintain-200-lux-minimum/2154 "2004-04-20T14:45:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Georg\_Mischler](https://discourse.radiance-online.org/letter_avatar_proxy/v4/letter/g/7feea3/32.png) [@Georg\_Mischler](https://discourse.radiance-online.org/u/Georg_Mischler)\
**Post date:** [April 20, 2004, 2:45pm UTC](https://discourse.radiance-online.org/t/radiance-simulations-maintain-200-lux-minimum/2154/1 "2004-04-20T14:45:12Z")

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Caroline Prochazka wrote:

> As my primary use of Desktop Radiance centres on the  
> changes in daylighting in a building as the glazing  
> type changes, should I expect to need a different -av  
> setting for each variation of the design?

As a principle, yes. Each variation will result in a  
different "general illumination level", which is what  
-av more or less represents.

> What is  
> likely to be the greatest factor in setting my -av  
> number - does it sound reasonable that for the same  
> buidling geometry, I will probably find the same -av  
> setting works throughout all glazing variations? Or  
> will it be the date/time/location setting which is the  
> biggest player? or something else?

If the primary variable is the transmittance of the  
glazing, then you can probably just scale -av linearly  
with that. If there are other modifications involved,  
you might still need to start experimenting from there.

-schorsch

> **···**
>
> --  
> Georg Mischler -- simulations developer -- schorsch at schorsch com  
> +schorsch.com+ -- lighting design tools -- [http://www.schorsch.com/](http://www.schorsch.com/)