# Daylighting simulations for different room depth

Dear Christopher,

Thank you for the comments. As ambient parameters options I have used:

-ab 12 -ad 50000 -as 2048 -ar 1024 -lw 1e-8 (following the 3-phase method
tutorial).

Otherwise, I think that the dropping of UDI due to the increasing of room
depth is not a strange effect. This because the contribute of the rays
refracted from the bottom wall is smaller.

Considering the –ab 12, it can be that the reflectance of the inner walls
and ceiling have a bigger impact compared with the systems as you said.

I suppose that also the dimension of the upper window, compared with the
lower one, does not have a great influece on the inner illuminance values.
Here the dimension http://s5.postimg.org/ezlt60cp3/lab.jpg.

The goal of this work it is to analyze the daylight level in a deep room
using a system of daylight redirecting. Therefore, I would like to have an
effect of the shading system after 4 meters.

Maybe I have to test different systems in order to reach the effects
expected.

Another question: Considering the characteristics of a real product I have
created this material for the light shelf

void metal shelf_mat

0

0

5 0.98 0.98 0.98 0.96 0.01

Can it be realistic? Do you suggest to use also a mirror on the shelf
and/or on the ceiling?

Thanks again for the help,

Giuseppe

···

2015-02-24 16:00 GMT+01:00 Christopher Rush <[email protected]>:

It could be that you need more -ab bounces, or more -ad rays traced in
order to avoid the unexplained divergence you see for the areas farthest
from the windows in the 10m deep room. This could also impact your drop
from 60% to 40% UDI when increasing room depth to 10m.

It’s possible that the solutions do perform similarly at more than 4m from
the glass, unless your lamella or your light shelf have special specular or
prismatic materials or shapes intended to really redirect light farther
into the space. By that distance from the window, the light has bounced so
many times that the reflectance of the floor and ceiling probably have a
bigger impact than either of two relatively comparable window systems. Or,
at that distance the illumination could be reliant almost entirely on the
view of the sky from each point on the workplane which could be similar for
both systems at a distance.

*From:* Giuseppe De Michele [mailto:[email protected]]

2. From the 4 meters the two systems seems to be equivalent. Can it
be since the systems do not influence the daylight trend from that distance?

3. Until the 7 meter, the daylight trend seems to be equal comparing
the three scenarios. After, we have the largest differences.

4. It is interesting to note as the UDI300-3000 on the 9 m pass from
the 60% of the working hours (image 45 - 9m) to almost 40% (image 45 -
10m) going under the UDI>3000 extended the depth from 9 to 10m.

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