Outdoor Microclimate Map issue

Hi everyone!

Thank you again for the fantastic tool you developed! It's really giving me a considerable help in developing my thesis work.
Last time I wrote here asking help about the evaluation of UTCI and PET through the "Outdoor comfort calculator" and "Thermal comfort indices" components and the analysis worked pretty well.

Now, since Chris (thank you!) added the "PET analysis Recipe" component to Honeybee, I wanted to define an outdoor microclimate map in order to compare the UTCI and PET and PMV (even though this one can be evaluated only for indoor conditions) indices and to evaluate more accurate results. I will then do the same simulation using an urban weather generator tool (Dragonfly maybe) in order to show the effect of urban heat islands on the outdoor comfort.

So, I wrote the definition for the above-mentioned analysis, trying to obtain something similar to what you can do with the software Envi-met, considering the buildings like uniform blocks with two generic materials (one for the walls and one for the roofs) and giving the ground zone a material with the proprieties of the basalt stone (since it is the main material in my analysis area). I also accounted the trees and the transparency of their canopies (using the definition that is on Hydra).
At last, I simplified the better I could the geometries of the buildings in my area, so that there are no problems with the exportation of the geometries to OpenStudio.

Unfortunately I have a problem with the Honeybee ComfortRecipe components and Grasshopper shows this message: "If you have connected a viewfactorMesh that includes regions on the indoor, you must connect up energy simulation data for zoneAirTemp, srfIndoorTemp, zoneAirFlowVol, zoneAirheatGain and zoneRelHumid" although I think I didn't set any indoor zones. Furthermore, when I connect these inputs to the Recipe component, the results seem to be weird and inexact.

Anyone knows what could be the problem? I think it is something about the geometries of my model, but I don't know exactly how I could fix it.

I hope I explained clear my issue.
I know that maybe the problem is more simple as I expect, but I'm quite new to these tools and I hope I can learn more asking for advice.

Attached you can find my definition with the internalized geometries.

I hope someone can help me and still thank for all your work.
Best regards,

Francesco

Attachments:

Microclimate map UTCI vsPETvsPMV Internalised.gh, 848 KB

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Replies to This Discussion

Permalink Reply by Chris Mackey on May 23, 2016 at 4:30pm

Francesco,

Your comfort evaluation surface definitely had some points that were inside the zone geometry. When the surface is right at the ground level, Rhino may think that the surface is actually inside the zone. I would move your comfort evaluation surface to be 1 meter off the ground in order to be representative of typical human height.

Also, you did not intersect the ground with the rest of the zone geometry, resulting in an incorrect energy simulation. After intersection, you also get one surface of the ground zone that is not inside any buildings. I fixed these two things in the attached file ad it works:

I would also recommend breaking the top surface of the ground up into sub-surfaces so that you can capture the variation in ground surface temperature that happens across the outdoors. Second, I would recommend putting some windows on your buildings as the exterior surface temperature of windows can be very different than that of opaque surfaces. Finally, you should keep in mind that the outdoor maps are assuming a very basic outdoor wind profile by default and, to accurately understand outdoor comfort, you really should be incorporating wind patterns after running a CFD. This discussion has some information about importing CFD from other programs to GH:

http://www.grasshopper3d.com/group/ladybug/forum/topics/import-cfd-...

-Chris

Permalink Reply by Francesco Scarpati on May 26, 2016 at 2:32pm

Hi Chris!

Thank you very much for your immediate answer and sorry if I could reply just today.
Unfortunately I couldn't see the picture you attached but I did anyway what you said and the definition is now working perfectly!
As regards the glazing surfaces, I wanted to try to define something similar to the Envi-met simulations, as I already mentioned, that's why I didn't put any glazing component in my definition. Moreover, I'm working in a XIX century urban context, so I assumed that accounting the glazing surface (that are just a little portion of the facades) wouldn't have changed too much the results of the simulation.
Regarding the CFD simulation, I didn't know that there was a way to evaluate it in Grasshopper (and this is one of the reasons why I'm using Envi-met to have results to compare with the ones of Ladybug and Honeybee). I will read everything in the link you posted and maybe I will write here again!

Francesco

Permalink Reply by Theodoros Galanos on May 26, 2016 at 8:55pm

Hi Francesco,

We are currently working on combining CFD results with LB/HB and Chris's wonderful tools. Experimentation so far has been quite successful and we are just waiting on a few example studies to release initial results.

I think it might be interesting to compare this method with a tool like Envi-met, which from what I understand is quite popular in urban micro-climate studies. If you want, I could assist you with setting up and running CFD simulations of your model. We could then pass the wind velocities into Chris's micro-climate analysis tools and compare the final results with what you have through Envi-met.

I believe this experiment could be valuable for all of us. Let me know if this sounds like a good idea and we can move it forward.

Kind regards,

Theodore.

Permalink Reply by Francesco Scarpati on May 28, 2016 at 1:55am

Hi Theodoros!

That sounds great for me!
I would be grateful if you could really help me in setting up the Grasshopper simulation!
I already set up the Envi-et stuff, I'm just waiting for the results (you maybe know that every simulation takes one day at least), so from now on it's all about working on Rhino/Grasshopper.

Looking forward to hearing from you soon.

Francesco

Permalink Reply by Theodoros Galanos on May 28, 2016 at 2:09am

Hi Fransesco,

That sounds good! I'll pass my email over and we can coordinate more on this.

I do understand the timeframe of CFD simulations no worries. The workflow we are working on also includes CFD simulations, using the open source OpenFOAM software. Given my usual hectic schedule, and depending on the size of your model, I think that it would take a few days to find a slot and run it.

The LB/HB part of the workflow comes after that and utilises the point wind velocities the CFD simulation provides.

Therefore, we can either compare that to your workflow utilising Envi-met or if Envi-met gives wind velocities (I must admit I'm mostly ignorant to its details) then we can also try and see how to insert that data to the workflow.

Kind regards,

Theodore.

Permalink Reply by Chris Mackey on June 13, 2016 at 10:10am

Francesco,

I just wanted to note that this conversation about the comparison of ENVI-MET and OpenFoam has a parallel thread here:

https://github.com/mostaphaRoudsari/Butterfly/issues/15

Also, you can find GH files for the outdoor comfort workflow that Theodore described on this conversation:

https://github.com/mostaphaRoudsari/Butterfly/issues/14

-Chris

Permalink Reply by Francesco Scarpati on June 17, 2016 at 11:16am

Hi Chris!
thank you for reminding me.
The discussion about the connection between grasshopper and Envi-met is getting really interesting.

Permalink Reply by Saket Sarupria on February 14, 2017 at 2:32am

Hi Francesco,

I have been trying to do an urban scale micro climate map. Would you mind sharing the updated working gh file. Would be really helpful to look at the correct workflow and implement if for my case.

Many Thanks!!

Saket

Permalink Reply by Chris Mackey on March 14, 2017 at 1:28pm

Saket,

The example files on hydra have been updated as of this past month and I think that this should fulfill your needs:

http://hydrashare.github.io/hydra/viewer?owner=chriswmackey&for...

-Chris

Permalink Reply by Saket Sarupria on March 22, 2017 at 9:14pm

Hi Chris,

Thanks a lot. Apologies for my delayed response.

Before your reply I managed to get the script working to get MRT and SET* values for a large urban scale model. The MRT I am getting are quite high (~65° from my script).

I actually wanted to reply back with results by running a test case on your script and the one I created to check if there are any fluctuations. Hopefully over the weekend I will get some time and do the test.

I am also planning to integrate wind results from BF by taking the same analysis plane for MRT and Wind Analysis. A bit time intensive but should be pretty straight forward. I will share the test case for review hopefully by the weekend.

Thanks for your help.

Regards

Saket

Permalink Reply by Chris Mackey on March 29, 2017 at 7:53pm

Sounds good, Saket. MRT values that high are common when you have a person standing in direct sun. Remember that MRT is a theoretical concept and not the actual temperature of any material. I'm looking forward to seeing the test case and I should mention that Theodore, Mostapha, and I have a paper under peer review right now that ountlines the most accurate way of doing this with Ladybug Tools. I will post a link here once it's past the peer review phase.

-Chris

Permalink Reply by Saket Sarupria on March 29, 2017 at 9:48pm

Hi Chris,

My Apologies. I still haven't got time to do the test case. A bit tight on schedule for few more days. The paper would be a great aid to justify use of using LB/HB to calculate Thermal Comfort. For final design submissions people are still relying on IES. I hope it will change soon.

Later on I hope I can run a test case both in IES and GH for comparison. Will update on that soon.

As always, thank you all for the wonderful work.

Regards

Saket

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