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

Model Translucent Panels on DesignBuilder

asked 2016-01-04 08:40:33 -0600

updated 2017-06-02 18:24:18 -0600


For a project, I have for the first time to integrate translucent panels into my model on Design Builder. For now I'm considering it as a glazing with its U-value, g-value and light Transmission factor. Is it correct to consider it like that, or is there a more correct way to include it in the calculations?

Thanks in advance

Best Regards,

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

answered 2016-01-04 11:26:57 -0600

If these are architectural panels, then modeling them as windows with matching U-value, transmittance, and solar heat gain coefficient or g-value is the best approach. Trying to model the architectural panels as a "normal" construction with material layers like other wall assemblies will NOT WORK, because EnergyPlus assumes that material objects are opaque (ZERO transmittance) according to the Engineering Reference for surface heat balance calculations.

edit flag offensive delete link more


Thanks for your answer. However, the translucent panels doesn't allow the direct solar gains to enter the area, but only the diffuse one. How is it modeled considering that?

NassimJ gravatar image NassimJ  ( 2016-01-05 01:57:24 -0600 )edit

In that case, you won't be able to use the Simple Glazing System object, since it is meant for specular (non-diffuse) windows (according to Engineering Reference doc). You'll need to create individual Glazing Material and Gas Material (if gas filler) layers to use in a Construction object to create the window assembly. The "Solar Diffusing" input field of Glazing Material objects is where you specify specular vs diffuse. This should only be diffuse for innermost glazing layer.

Aaron Boranian gravatar image Aaron Boranian  ( 2016-01-05 10:40:54 -0600 )edit

So in my case, I should consider the translucent panels as a wall, and apply the properties of the polycarbonate panels directly there? Makes sense, because now the solar gains are overheating the spaces, which should not be the case. Thanks for your answer ;)

NassimJ gravatar image NassimJ  ( 2016-01-06 02:06:47 -0600 )edit

When you say "should not be the case", do you have a measurement result that translucent panel does not overheat the space?

Ery Djunaedy gravatar image Ery Djunaedy  ( 2019-03-16 06:56:25 -0600 )edit

Hi Ery, Not excatly what I meant. I want to say that a translucent panel would block sun compared to a glazing as the proportion of direct and diffuse radiation getting in aren't the same. Not measurement, no proof here though..

NassimJ gravatar image NassimJ  ( 2019-03-26 10:56:42 -0600 )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


Asked: 2016-01-04 08:40:33 -0600

Seen: 297 times

Last updated: Jan 04 '16