Ladybug shading designer

shading

#1

Hi

I’ve been playing around with the shading designer but am getting some weird results. I’ve been tasked with finding the ‘optimum’ shading (Horizontal or Vertical) for a building in Sydney for the various aspects (N/E/S/W). What is the best way to achieve this with Ladybug?

Is it best to create an analysis period for the entire year or only summer solstice? I used 21 Dec (summer solstice) and feed the sun vectors into the shading designer component, the resultant geometry is pretty extreme (refer below) and doesn’t respect the normal of the surface or the scale of the building (i.e. no max depth). Alternatively, if I feed in depth instead, it seems to just generate shading automatically but no optimisation is happening? How do you test the fitness of shading - with the comfort shading benefit component? Or do I need to use Galapagos or something like that?

Thanks

P


#2

Hi @PaulWintour,

I would recommend you use Ladybug_SunShades Component. Here’s an example. SunShade.gh (414.9 KB)

Defining a shading period is crucial and there are many ways you can go about it.

  1. The whole period between the equinox and the summer solstice.
  2. You can look at the Heating degree days and the cooling degree days. The intersection of both curves can be your shading period.
  3. Conduct energy modelling and find out when the building requires cooling the most. This cooling load will account for not only heat gain from the envelope, but also internal heat gain from people, equipment, lights. It would be a good idea to reduce envelope gain as much as possible during this period.
  4. You could also use one of the comfort models.
  5. In the sample file attached, I used a dry bulb temperature cut off.

Hope this helps.


#3

With fins as shading surface.

SunShade.gh (505.2 KB)


#4

Made minor changes in the component to enable changing pergolas.

SunShade.gh (503.2 KB)


#5

@PaulWintour ,

@devang’s suggestion of the sunshades component is definitely better than the original shading designer. Still, you will likely find that the “optimal” shade depth is something that is not easily construct-able, particularly on the east/west, where you can easily get “optimal” overhang depths in the range of ~5 meters. For this situation, it might be better to run a shade benefit study that shows you the regions that are most important to shade. You have to assemble an energy model of your space but this is the workflow that I have found most useful for people who have asked me for an “optimal” shade depth:
http://hydrashare.github.io/hydra/viewer?owner=chriswmackey&fork=hydra_2&id=Energy_Shade_Benefit&slide=0&scale=1&offset=0,0

-Chris


#6

Thanks @chris for joining the thread!
To add to what Chris said, on the East and the West sides, I would really recommend looking more into fins. The sun in the East and West is usually low in altitude, and therefore overhangs easily miss those suns. Probably a combination of fins and overhang would be a good solution.


#7

This paper provides a good review of different approaches.
http://www.ibpsa.org/proceedings/BS2011/P_1209.pdf

As other mentioned, you can use any of the suggested workflows that fits your problem using Ladybug or Honeybee.