Shading Definition

Hi all,

I have a question about shading definitons.

My model (simple box) has two windows, a big one and a smaller one (the small window is approximately in the middle of the big window -> see attached file).

I want to shade both windows seperate with electrochromics (switchable), so I set two shading groups with the corresponding nodes.

Question: Where/How can I define which shading group is for the corresponding window ( Shading Group 1 - big window, Shading Group 2 - small window)?

Question 2: I've done Timelaps simulations with only one shading group and unlocked the "Hide Dynamic Shading" to see if one of the windows (or both) is changing, but none of them does?

Thank you and best regards,

Jakob

Tags: electrochromics, shading

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Attachments:

Test.3dm, 142 KB

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Permalink Reply by J. Alstan Jakubiec on December 17, 2015 at 6:02pm

Hello Jakob,

The electrochromic (switchable) controls are setup by material names. So if you need to control two window groups (or windows) separately, all you need to do is to create two 'clear' state materials in your .\[RhinoFileName] - DIVA\Resources\material.rad file. For example,

void glass Glazing_Electrochromic_Clear_60_BigWindow
0
0
3 0.6541 0.6541 0.6541

void glass Glazing_Electrochromic_Clear_60_SmallWindow
0
0
3 0.6541 0.6541 0.6541

Then those two materials get assigned as the base glazing material for each shading group.

Question 2: I've done Timelaps simulations with only one shading group and unlocked the "Hide Dynamic Shading" to see if one of the windows (or both) is changing, but none of them does?

Dynamic shading only works in the climate-based calculations. This option in DIVA is meant to allow people to render blinds, for example, which would ordinarily be hidden if a part of a dynamic shading control. If you want to see the visual impacts of the state changes, unfortunately a timelapse animation won't show you that unless you manually configure it per rendering.

Best,

Alstan

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Permalink Reply by Jakob91 on December 23, 2015 at 7:16am

Hi Alstan,

Thank you! This helps me a lot.

I set the shading and lighing controls and ran Annual Glare and Climate-Based metrics. Everything works fine, even the thermal simulation runs perfectly. But the result of the thermal simulation is strangely high.

8.166*e^8 = 24,342.5 kWh per month?

I've seen the tutorials and tried it with the reference model. Same problem. (should be about 550-600kWh per month, but I get 16,000kWh)

Did I forgot something or are the properties wrong? (units in meters)

Regards,

Jakob

Attachments:

Test.3dm, 234 KB

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Permalink Reply by J. Alstan Jakubiec on December 26, 2015 at 10:14pm

Hi Jakob,

No -- you did not forget anything! There is an intermittent bug that reports units in J rather than kWh. To fix, you can replace the c:\DIVA\Scripts\diva-thermal_results-conversion.py file with the one attached. This should be permanently fixed in our next release, sometime in first quarter 2016.

Best,

Alstan

Attachments:

diva-thermal_results-conversion.py, 7 KB

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Permalink Reply by Jakob91 on January 28, 2016 at 10:57am

Hi Alstan,

This is great, all simulations run perfectly! Thank you.

For my thesis I need a control strategy which considers glare. Shading type is electrochromics.

When I set the operation to Manual, my shading(glazing) states switch to the next state when the value DPG>0.4, right?

Question: From which value does it change back to the next lower state?

Another option is the Automated Glare Control. There are some points I have trouble with.

You need to select a second, exterior illuminance sensor. So you need a sensor grid that is both, inside and outside the room/window? My interior sensors have been vertically aligned... Copy, paste and move doesn't seem to be working. When I run an Illuminance simulation only the new grid shows results.

Is a horizontal grid the only way?

The description says that when the facade illuminance gets above a user defined threshold, the system will be fully closed to avoid glare. So in an electrochromic controled shading system, as soon as the illuminance raises obove the threshold, without an intermediate step, the maximum shaded material would be activated?

The threshold of the glazing states are for regulating the interior illuminance (which later influence the artificial lighting and the energy consumption, right?), but it is not possible to control the glare or even the temperatur with it, is it?

Thanks for your time.

Regards,

Jakob

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Permalink Reply by J. Alstan Jakubiec on February 2, 2016 at 8:42am

> Question: From which value does it change back to the next lower state?

It is a 'manual' control type, so it will not change back until the beginning of the next day.

> You need to select a second, exterior illuminance sensor. So you need a sensor grid that is both, inside and outside the room/window?

You can just create two separate sensor grids, one based on the floor and one based on an outside surface. Just select two surfaces when you generate your sensor grids.

> So in an electrochromic controled shading system, as soon as the illuminance raises obove the threshold, without an intermediate step, the maximum shaded material would be activated?

Yes, when the sun is also within the altitude and azimuth ranges defined.