Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question
4

How can I model daylight effect of a light well under landscape pond?

asked 2014-10-14 20:38:20 -0500

yongqingzhao gravatar image

updated 2014-10-15 01:03:57 -0500

I have a project,whose light well is under the landscape pond.The depth of the water in landscape pond is approximate 40 cm. I have tried to use glass instead of water in ecotect,and set a transmittance for glass.But how can I get the transmittance data about water? Where is there any related research data about water transmittance ?

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
3

answered 2014-10-15 14:09:30 -0500

updated 2014-10-15 14:12:59 -0500

Here's a partial Radiance scene description for a swimming pool that uses the 'dielectric' primitive:

# pool.rad

void plastic white_paint
0
0
5 .5 .45 .4 0 0

# pool water
void texfunc wavy
6 wave_x wave_y wave_z wave.cal -s .25
0
1 .05

wavy dielectric wavy_water
0
0
5 .9 .9 .91 1.33 0

# wavy glass wavy_water
# 0
# 0
# 4 .9 .9 .91 1.33

# genbox white_paint pool 3 5 1

[etc...]

(source: http://radsite.lbl.gov/radiance/diges...)

This suggests that the RGB transmittance of water is ~90%, which is a good starting point. Next, you're modeling as "glass" instead of "water" (or in Radiance parlance: "dielectric"), so you need to add a factor for the water depth and turbidity, among other things. This is where it gets messy, but some interesting references I saw are this and that.

Good luck/have fun! - Rob

edit flag offensive delete link more

Comments

Thank you very much.It's very useful!

yongqingzhao gravatar image yongqingzhao  ( 2014-10-15 21:03:37 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

 

Question Tools

1 follower

Stats

Asked: 2014-10-14 20:38:20 -0500

Seen: 364 times

Last updated: Oct 15 '14