Self Shading perforated dia-grid screen.

Hi everyone

Long time forum browser but my first post. I am part of a student team working on a house prototype constructed predominantly of EPS foam. We are participating in the solar decathlon china competition this year where we will be constructing the complete house.

http://www.heliomet.org/

The house has always had the notion of large self shading screen on its south facade. However the self shading aspect of this had never really been developed and it was only ever really an extruded pretty dia-grid pattern.

Ultimately we imagine the perforations to be milled out of foam which could then be laminated in a surf board kind of fashion.

I have done some work with optimization through geco and galapagos before, so I imagined I could do something similar to optimise the openings for maximum radiation in winter/minimum in summer to the internal space.

Because of the nature of the pattern and large number of perforations though, each time galapagos will try a different iteration, it has to trim all the openings on both faces of the screen, or boolean difference for it to be meshed and exported. Whicever way i do it, it just seems too heavy a process for testing iterations.

I've also thought about maybe optimising a single opening, or set of openings, and then trying to combine them back into an overall.

I have attached the grasshopper file I was messing around with, where i was predominantly just looking at a dia-grid on front on back face of my 'screen' with a number variables to manipulate them. Lofting between the corresponding shapes gives some idea of a pattern with more '3 dimensionality' and interest. As I said, once i started trying to set this up ith geco/galapagos to look at shading optimisation it was way too heavy.

I would just be interested in anyones take/experience in how to approach this self shading project in grasshopper, to get me started on a good path as I'm sure there are better ways i dont know of.

Thanks

Arrash

Attachments:

Replies to This Discussion

Permalink Reply by Luis Fraguada on March 12, 2013 at 1:07pm

Start with meshes...when working with lots of computation, meshes will calculate much faster!

By the way, how are you 'optimizing' this? What are your evaluation criteria for natural lighting? Are you looking at daylight autonomy? Are you doing thermal calculations?

I have not seen too much funkyness at SD, but this house sure would be interesting.

Permalink Reply by Arrash Fakouri on March 12, 2013 at 1:42pm

People werent kidding when they said how helpful people were on GH forums!

Meshes..yeah...exactly i'll do that first at least.

In terms of criteria for evaluation, it is all up for development really. Ultimately I guess i want the internal quality of the space in terms of not overheating, good daylighting etc. etc. to be as good as possible. I really need to consider all of this in more detail.

And yeah we definitely think we can be up there in terms of funkyness/innovation at the competition this year, though we may not be able to compete in terms of expensive equipment etc.

Permalink Reply by Phil Kolbo on March 12, 2013 at 1:17pm

Without looking at your definition.....

I don't see why galapagos is needed in this instance. Break your shading face down to a grid of panels. Take a sample set of daylight vectors (for example take 20 samples per day, 50 days out of the year for 1000 samples) from each panel and calculate the % of occlusion. Allow that % to be the % "open" of each panel. Design the opening in each panel to be something cool and proportional. Profit.

You could even break it down by a finite number of available panel types(say 0%, 20%, 40%, 60%, 80% open) and create an efficient production. All of these things can be paramterized to allow for more samples or more panel types as needed or based on your calculation limits.

The only exception would be proper environmental analysis, say, if you were trying to reduce solar gain in summer and allow for it in winter. You would want to split this calculation between when you need to be gaining heat and where you want to be shading. Then extrapolate the percentage between the two. You may even need a gradient of heat gain through fall/spring. The possibilities depend on how much you know about the mechanical requirements of the area/building.

That would be my approach. If I have more time tonight I will try and put something together on this as its been something I'd like to have in my back pocket....

Edit: You would also need to analyze the angle of incidence as it could have an effect on the amount of solar gain.....

Permalink Reply by Arrash Fakouri on March 12, 2013 at 1:53pm

yep I dont know that galapagos is needed either, its just the only approach to this kind of subject area i have experienced before.

No rush to put something together! but your input is very much appreciated. We need all the help we can get on this project, very small team and many tasks :) I will take a look into this sort of approach to, I think i get the jist of it.

we're soon to have meetings with our environmental engineers so in terms of mechanical requirements I can hopefully get better information out of that.

Permalink Reply by Arrash Fakouri on June 9, 2013 at 4:46am

Thanks for the help a few months ago guys. Thought I'd share the link to my blog so you can see where it progressed (scroll down a bit and you should see it). To be built in china very soon.

http://asd-ddrs.org/arrash/

RSS