Daylight when holes between two blocks +Vertical Sun shading

bdabdesign · Posts: 14

Dear All,

I'm doing some calculations on vertical sun shading. The fascade will have big windows starting 0,8m from the floor. The window will be about 1,4m high. Then there will be piece of wall again, and then a new window about 0,6 m high. The vertical sun shading device will totally cover the top window, and just the top bit of the lower window.
The windows will have different types of Total solar transmission.

Please see attached file to see what I mean.

To be able to simulate this, I've made a component block and altered the transmittance.

Now to my questions.

1. Is it correct that I can't simulate the daylight when I use the component block as shading device? My plan is to replace the vertical component block by horizontal shading which will have the same affect on the lower window. The top window will then have another horizontal shading. Otherwise I will have to change the characteristics of the top window so it matches the window + horizontal shading.

2. To be able to have different type of windows on the same wall I had to build every floor by creating two blocks, and then make a big hole between the two blocks and then merge the zones. Is this the best way to build the model?
3. Can I trust the daylight factors being calculated when I build the model this way? Since I choose the working height in the lower block I assume this will be correct. And I see that the daylight factors increase after I’ve made the hole and merged the zones. But I want to be sure.

4. Any other ideas on how to model this in a easier way?

Thanks in advance.

Regards
Mattias Jönsson, Sweden

Andy Tindale · Posts: 2617 Location: Stroud

Dear Mattias,

1. One concern I have from what you say is that varying the component block transmittance will not have any effect on Radiance calculations - this only affects E+ simulations.

2. You can set the properties of individual windows and other openings so this complex approach should not be necessary.

3. Otherwise yes you can trust the daylight factors.

Andy

bdabdesign · Posts: 14

Dear Andy,

Thank you for replying so fast.

1. That's what I thought, that's why I have to find an alternate way to model this. The vertical model is to find the right hight and position for the sun shading. When I'm running the daylight simulations I will have to model it with horisontal local shadings since this will have effect on the Radiance calculations, right? Will the Radiance calculations also take into account if I change the blade material from let's say steel to glass?

My plan is to simulate the total SHGC for both the top window and the sun shading in an external program, and then set that as the SHGC value for the top window in DesignBuilder. Then the horizontal local shading will simulate the vertical one. This should work as long as the angle from the window to the outer part of the sun shading is the same. And of course, the characteristics of the material are the same.

2. I've tried that, but then I need to hold down ctrl + click on all the big windows on all for sides of the building. That's fine one time, but when I want to see the effect of changing the length of the shading, I will have to do it over and over again.. Or is there a better way of highlighting all the windows of one kind?

3. That's great news, thanks!

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