Hi DIVA team,

For the LEED v4 daylight option 1, about sDA simulations, the movable blinds/shades should be included.

As far as I can see, inclusion of blinds is not implemented in DIVA, yet? In version the alpha version 3.0 it is option 2 (point-in-time analysis) that is implemented.

 

I would like to hear if you, based on your experience with LEED and IES LM-83-12, see the work-flow below as a feasible simulation procedure? Furthermore, I would like to hear if you'd approve our description of the fabric as a trans material?

Any recommendations is of course also always appreciated ;-) 

 

1)

Run our ASE analysis with only the static shading. From this we subtract the hours when additional shading is needed, meaning hours with direct sunlight above 1000 lux according to IES LM-83-12.

Output 1: hours with need for additional shading.

 

2)

Run two sDA analysis, one with only static shading and one where blinds are activated.

The movable shades, are in our case fabric (we do not have a BSDF-material), and we'll simulate this by a trans material, where

 

modifier trans id

0

0

7 R G B specularity roughness transmissivity transmittedSpecular

RGB values describe the colour of the fabric

Specularity and roughness are the visual characteristics of reflected light, assumed to be 0 0, unless other is specified

transmissivity = the total visual transmittance x conversion factor (1.09)

transmittedSpecular = is the openness of the fabric.

 

Output 2: Two annual simulations - one with and one without shades/fabric

3)

Post processing - combining the output from 1 with the output from 2.

Thanks in advance,

Anne

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Hi Anne,

As far as I can see, inclusion of blinds is not implemented in DIVA, yet? In version the alpha version 3.0 it is option 2 (point-in-time analysis) that is implemented.

It is implemented under the Daylight Grid-Based > Climate-Based > LEED v4 sDA + ASE option. We use the conceptual Daysim shading model for the shades down states under IES-LM-83.

Your workflow not only sounds feasible, but it is exactly what DIVA is doing except with a different shade-down model.

Best,

Alstan

Perfect - thanks!

Hi Alstan

I've got some additional questions for this LEEDv4 simulation.

1) What is the difference with the sDA+ASE and the LEEDv4 sDA+ASE simulations?

2) If I want to specify a material for the dynamic shading (different types of curtains etc), is it going to be implemented in the interface or can I change it in one of the the material files before simulation?

Best regards

Mathias

Hello Mathias,

Those are good questions. In the case of no. 1, there is no difference. The results just get processed according to the LEEDv4 requirements of sDA_300lx_50% being 55% (or 75%) of floor area and ASE_1000lx being less than 10% of floor area.

For no. 2, it is not possible at the moment, but it is a good idea and certainly feasible. Right now, we are using an ideal model from the Daysim software which is very fast but does not use a material definition nor rely upon a separate raytracing operation. I think it is a great idea to implement your idea of a material replacement for the dynamic shading portion.

Best regards,

Alstan

Hi again

Just a few suggestions. We are setting up a large office building and it's got a lot of measure nodes for the LEEDv4 sDA+ASE.

With the "set node groups" setup, I have two ideas for improvement:

1) I miss a way to hide objects/layers when targetting my node groups. currently i can hide a layer but maybe if diva would save a layer state before picking the node groups and then restore the layer state when picking is finished, so that people can hide layers temporary in the process (i have a ceiling above and context etc etc).

2) when having a lot of node groups, I have to scroll a lot in the dialog, as the "set new group" button is in the bottom, it would be appreciated if this button was moved to the top

And we've just set up a decent shading material based on the roller blinds we are going to use. I was just thinking if one could make a layer (or pick several layers) that could have the shading objects on them, so that diva would enable that layer for the shading simulation instead of the basic shading currently.

Hi Mathias,

Thank you for your feedback -- those are all great ideas. We already hope to implement the material-based shading option and I like your interface suggestions.

I also have a question for you: When setting up large numbers of control groups (>25) do you experience any problems with the display of the interface? On my computer, it causes Internet Explorer to glitch and I wonder if it is a global issue.

Thank you,

Alstan

Hi Alstan

I havent seen any problems with display on this computer. Just did a test with 33 groups and some internet explorer, no problem.

We are running win7 with quadro200 graphics cards here in the office, using nvidias "performance" drivers.

Mathias

To speed up my process, I would love the possibility to have the interface automaticly (or ask) import the 300lux-nodegroups, so that one nodegroup=1 surface, at first. THEN use the interface to make manual override.

Oh, and when adding a nodegroup and not selecting any nodes, it quits the setup, so one has to click mertrics again. It would be nice if the setup just opened as before clicking the add button

M

Hi Alstan,

I have this kind of problem. I am trying to set more than 24 control groups, when I select the 25th control group, the visualization of  the Diva´s window changed and doesn´t allow me to select any other node. Could this problem be related to the overall number of node points?

Thank you for your help

Stefania

J. Alstan Jakubiec said:

Hi Mathias,

Thank you for your feedback -- those are all great ideas. We already hope to implement the material-based shading option and I like your interface suggestions.

I also have a question for you: When setting up large numbers of control groups (>25) do you experience any problems with the display of the interface? On my computer, it causes Internet Explorer to glitch and I wonder if it is a global issue.

Thank you,

Alstan

Hi Stefania,

Thank you for your feedback.

No, it shouldn't be an issue with the number of sensors. It seems to be an problem with Internet Explorer (which the selection interface is displayed in). I'll have to look into this more carefully for the next beta-release iteration.

Thanks,

Alstan

Hi Alstan,

You write that Diva uses the conceptual shading control for LEED v4 sDa simulations.  Is the conceptual shading control used for all the daylight autonomy simulation options (eg daylight autonomy, continuous daylight autonomy, spatial daylight autonomy)?

Because an actual building will not have shades that are exactly like Diva's conceptual system, I am interested to see the DA result without any shades.  This will let me understand how much the shades influence the result.  Is there an easy way to do this?

I thought I'd be able to do this by running 2 simulations - one with "Daylight Autonomy" and the second with "LEED v4 sDA + ASE". In the first simulation, I tried to use the same settings to match the second except with no dynamic shading. For a side lit office space facing south, the first simulation (daylight autonomy) has a higher mean DA than the second (LEED v4).  For the same room facing north, the first simulation had a lower mean DA than the second.  I'm not sure how to interpret these results.  Your input is appreciated.

Regards,
Marc

 
J. Alstan Jakubiec said:

Hi Anne,

As far as I can see, inclusion of blinds is not implemented in DIVA, yet? In version the alpha version 3.0 it is option 2 (point-in-time analysis) that is implemented.

It is implemented under the Daylight Grid-Based > Climate-Based > LEED v4 sDA + ASE option. We use the conceptual Daysim shading model for the shades down states under IES-LM-83.

Your workflow not only sounds feasible, but it is exactly what DIVA is doing except with a different shade-down model.

Best,

Alstan

Hello Marc,

Is the conceptual shading control used for all the daylight autonomy simulation options (eg daylight autonomy, continuous daylight autonomy, spatial daylight autonomy)?

No -- you can setup advanced shading for all of the other simulation types. The sDA calculations will allow more advanced shading options in our forthcoming 4.0 version.

The sDA metrics by default has a shading system that will close whenever more than 2% of the room floor area is lit by direct sunlight. This is the reason you get lower values for the sDA calculations rather than a DA calculation without shading. We have an entire presentation and panel discussion on the new LEED Metrics, which you can find below.

LEEDv4 panel discussion [presentation] [mp3 audio]
Kevin van den Wymelenberg, Ed Clark, Eddy Santosa
Moderated by Alstan Jakubiec

All the best,

Alstan

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