I am testing Diva4 components, especially sDA&ASE output. And I notice some abnormal results when I rotate my testing space/window towards the range from East (90 degree) to South (180 degree). Within this range, sDA&ASE are sort of underestimated. But if I rotate the space to other orientations beyond this range, the results look reasonable to me. I've attached test files for your verification. I also run Diva4 in Rhino to double-check and notice the results generated within Rhino are reasonable.  

I'd also like to know, in Grasshopper, how I can trigger sDA Conceptual shading control. 

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You got the gist of it.  In manual mode, the presumption is that users draw the shades the moment they experience visual discomfort, and leave them down for the rest of the day.  The shades don't get opened again until the following morning, when occupants re-enter the office.

Those shading schedules look pretty typical of a South facing window in the Northern hemisphere.  During the summer, the sun is high, and doesn't penetrate deeply enough to cause discomfort.  Hence the shades can stay open.

(And yes, in my 89.4% sDA result, the shades were in Manual mode.  Of course, as I pointed out, the lack walls or furniture is a fantasy.  I also think I used a 90% white material for the louvers, which is, um, not going to happen.)

Cheney said:

Hi Jon, 

Actually I do not quite understand the shading schedule map generated from the sample DIVA4 project: 

1. By using manual shades, the shades mostly closed at daytime and night time but totally open from Apr to Aug? Is it because the low sun in winter and higher sun in summer (south orientation)? I understand manual control means when someone sitting near to the window has potential glare issue and trigger manual shades, it will not be open again for the rest time of the day until next morning? But how can I interpret the shades will never be closed during shoulder and summer months below? 

2. By Auto, it makes more sense. Nighttime will be open, daytime will be closed when get direct sunlight

 I guess my question is, under what circumstance, we have to use manual control? For your sample sDA/ASE simulaiton with overhangs, does it trigger manual shades in the calculation and still be able to achieve  sDA=89.4%?  

Hi Cheney and Jon,

I have seen that you were discussing about the difficulties to fulfill both sDA and ASE in LEED v4. I'm very interested in the topic since I'm working in some studies to see how we can achieved both sDA 55%-75% and ASE<10%. It would be really nice to know more about your parametric tool Cheney, and if you found a room which fulfill both requirements and what are the characteristics of that "ideal" room (dimensions, shading, reflectance....)

On the other hand, it is being hard to find examples of buildings which are ok in both metrics, as well as discussion about this topic. So, if you know about any forum where I can find people talking about it, I will appreciate :) I already had a look on LEED forum but I didn't find exactly this topic :(

Looking forward to knowing about any new information you may have :)

Thanks in advance!


Cheney said:

Hi Alstan and Jon, 

I am developing an early stage tool in which octopus is used to optimize room depth, shades dimensions, etc. in order to achieve both sDA>55% (or 75%) and ASE<10%. I am doing it orientation by orientation so that I am able to understand, with current window dimensions, how deep the daylight can be introduced without too much direct sunlight at each every orientation.

From your experience, is it easy to fulfill LEED v4 requirement, I mean both sDA and ASE? Is there any successful design can prove it? Until now, I have not seen a successful case and my concern is the current sDA and ASE requirements they are contradicting each other and make it impossible to achieve both. Your thoughts will be greatly appreciated.

Regards, Cheney     

Jon Sargent said:

Alstan is right about this -- ASE should ignore the dynamic shade, so those ASE values should be higher (and remain unaffected by the shading schedule).  The correction is reflected in the latest DIVA auto-update (v4.0.2.11).


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