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Is it possible to use EMS to change the construction of the shade?

asked 2021-03-02 17:07:37 -0600

uuiiek gravatar image

Hi there,

I am wondering if it is possible o use EMS to alter the shade construction?

I can define a window with shade construction in the window control object, but it appears that I am unable to modify this construction by EMS once it is set.

I was thinking about instead of window shade control, I just assign the construction with shade to the window surface and then use EMS to dynamically change window construction. However, this failed also because "Window must not directly reference a Construction with a shading device. Use WindowShadingControl to specify a shading device for a window."

I am quite stuck here because I cannot think other alternatives.

Does anyone know how to get around this? If not, any anyone know what are the equivalent solutions?

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answered 2021-03-03 10:33:08 -0600

updated 2021-03-03 11:13:15 -0600

As of E+ 9.4, a window may reference multiple WindowShadingControls/Shades. You can then set each WindowShadingControl's shading control type to OnIfScheduleAllows and define schedules across the multiple WindowShadingControls such that only one shade is active for a given period. If you don't know the schedule in advance, you can use an EMS program to actuate the schedules.

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gotcha. I am wondering if you have any exmaples?

uuiiek gravatar image uuiiek  ( 2021-03-03 10:38:27 -0600 )edit

Here is an example IDF that uses different Shade objects for summer vs winter for all windows.

shorowit gravatar image shorowit  ( 2021-03-03 11:01:22 -0600 )edit

I see. thank you for the help and I'll give it a try later today...

thank you very much.

uuiiek gravatar image uuiiek  ( 2021-03-03 11:11:42 -0600 )edit

so if I understand correctly, before 9.4, one window can only have one shade control object. After 9.4, one window can be referenced by multiple window objects. Is this correct?

uuiiek gravatar image uuiiek  ( 2021-03-03 11:15:14 -0600 )edit

answered 2021-03-03 08:20:37 -0600

rafael.alonso gravatar image

You could calculate your window+shading properties using LBNL window or following EN ISO 52022-3:2017, and input them as a WindowMaterial:SimpleGlazingSystem. Depending on what you are after, this could be accurate enough as far as I know.

Then, you can use the EMS to switch between the construction assigned to your window with the EnergyManagementSystem:ConstructionIndexVariable.


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thanks. i guess that;s the alternative then if changeable shade is not possible

uuiiek gravatar image uuiiek  ( 2021-03-03 10:53:50 -0600 )edit

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Asked: 2021-03-02 17:07:37 -0600

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Last updated: Mar 03 '21