shades generated by Window Shades Generator are not shown by Decompose by Type

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Permalink Reply by Abraham Yezioro on July 26, 2015 at 12:24am

Well Grasshope, I think you are rising a point that has some issues.
I'm also surprised the geometry is not there. But checking the hints of the component i'm seeing how it works (not that i definitely understood fully).
First, i created the IDF to see what is going on there. I see that the component contributed a Blind deinition. The blinds are not geometrically defined, only as shading elements for the window. So for me this is a good think since a was not aware of it.
If i understood right, in order to get the geometry you need to have a simulation done and some of the results connected to the ZoneData inputs (Chris will explain broader this point, i'm sure).
So what i will do in your case, until further notice, is to take the ShadeBreps output and connect them to a HB_EPContextSrf component. For your simulations DON"T connect (or use) the HBObjWShades output of the EPWindowShades to the runEnergySimulation (or any other component that uses or changes the zones definitions), but instead use the previous component (in your case the HB_glazingCreator).
Messy enough ...? :-)

-A.

Permalink Reply by Abraham Yezioro on July 26, 2015 at 12:28am

See attached, so it is more clear ... hopefully.
-A.

Attachments:

• tut_test_v039_ZJ_AY.gh, 516 KB

Permalink Reply by Grasshope on July 26, 2015 at 1:02am

Thank you very much, Abraham!

I also got similar understanding reading the notation of the EPWindowShade component which is to generate shading control definition for a window, rather than creating shading geometry specifically. 

The shadeBreps geometry output from this component can be used as HBContext object, but it will lose all the shading control definition and become pure obstruction geometry.

So, we either use the EPWindowShade component to define blinds for windows, or use the shading geometry created as HBContext geometry, but not both at the same time such as the the case in your GH file which will create double shading for a window.

Am I correct?

Permalink Reply by Abraham Yezioro on July 26, 2015 at 1:26am

Not quite.

The case i sent don't use "double" shading. Notice that the i didn't use any further the output of the HB_EPWindowShades component.

But if i will i can have both (Blinds andexternal shades).

You can have some control in the external shades applying transparence schedule to the context component. There is a very good video tutorial from Chris on this one.

-A.

Permalink Reply by Grasshope on July 26, 2015 at 2:01am

Pardon me, Abraham, for not noticing that in your GH file the HBObjWShdes output of the EPWindowShade component is not used as the input for Energy Simulation component!

This begs another questios: What does the shadings output in the decomposeByType component refer to?

In OpenStudio, shading surface (or overhang) can be generated for individual window surface based on projection factor. Is this type of shadings that can be shown using the decomposeByType component?

Permalink Reply by Abraham Yezioro on July 26, 2015 at 2:07am

I assume (but i might be wrong) that those shadings are geometry WHEN you use the ZoneData inputs for the HB_EPWindowShades. then, instead of Blinds the component creates Shading Devices.

Again, this is my assumption. I didn't try doing the simulation and inputting those.

A more educated response will come from Chris on this respect.

-A.

Permalink Reply by Chris Mackey on August 1, 2015 at 9:15am

Hey Guys,

I am sorry that I am so late to the discussion and I really should have stepped in to make things clear earlier.  It seems like you figured out generally how the component is supposed to work and I will just clarify some of the details.  I will also note that I do not know what the shadings output of the decomposeByType component is supposed to do as Mostapha put it there a long time ago and I was not sure what his intentions were. Going down a list of clarification points:

1) You are right that you should either connect up the shade breps to the EPContext component or just plug the HBObjwShades into the RunSimulation component (never do both).  However, connecting the breps to the EPContext component is greatly undesirable for two reasons: It will make the simulation run much longer and the energyPlus calculation will not account for the surface temperatures of the blinds (it will assume they are the same temperature as the outdoor air, which is very wrong in a lot of cases).  When you connect up the HBObjwShades to run the simulation, EnergyPlus will understand the blinds as abstract objects defined only by a numeric parameterization and not as actual geometry.  This enables the calculation to run fast and is also enough of a description that E+ can calculate the temperature of the blinds, thereby accounting for the heat that can be re-radiated from the blinds to the indoors when they get hot in the sun.  This more desirable way of running the blinds was how I imagined the component being run most of the time and I mostly included the shadeBreps so that you have a visual of what you are simulating.

2) When you use the more desirable HBObjWShades to approximate your blinds, you should use the blindsSchedule input in order to tell E+ when the shades are pulled (this is instead of the transShcedule on the EPContext component).

3) The zoneData inputs on the EPWindowShade component are meant to help in an entirely different workflow, which evaluates shade benefit based on energy simulation results.  I apologize if it seems confusing to have two major uses of the component in one but we have so many Honeybee components right now and I did not want to make 2 separate ones when they seemed so similar.  See this example file to see how to do energy shade benefit (https://app.box.com/s/oi64zoj5u1slz494grzhgmdkx7yie9jo).

Ok.  I think that clears up everything that I know. Now to the part that I do not.  As I said, Mostapha put in the shadings input there a long time ago and I do not know what his intentions were.  Abraham, as you know, I am about to do a major revision of the EPWindowShade component to make it compatible with OpenStudio, include drapes/generic shades in addition to blinds, and I also should figure out how to do electrochromic glazing.  I can easily include all of the visualized shades as output from the decomposeByType component when I do this.  However, I do not want to interfere with other intentions Mostapha had when he put the input in.  If he could confirm that this was in-line with his vision for the shadings output, I will implement it soon.

-Chris

Permalink Reply by Abraham Yezioro on August 1, 2015 at 10:41am

Thanks Chris,

As usual, very thorough answer.

-A.