I built a 1x1x1 m. cube, with faces to N, S, W, E, then calculated the incident radiation for each face. Shouldn't E & W faces diplay the same results?
I get the same available radiation for both, but since I get different shading percentages for each face, the incident radiation values are not the same... What is wrong here??
| Attachment | Size |
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| cubo.eco | 123.53 KB |
Sahding Mask
Francisco,
No, you would only get similar radiation values if you were using a clear sky model. But Ecotect uses an actual weather file that accounts for atmospheric element such as clouds and fog. Hence, your morning facade may receive less radiation thatn the afternoon if your location experiences morning fog (prevalent on the West coast of the US), or less on the West facade in some tropical location due to the increse in cloudiness at that time of the day.
Best,
Olivier
there must be something
there must be something else. I get differences between East and west faces of about 30%. I run the same test in Energy Plus (same weather file of course)and get less than 5% difference...
The Average shading percentage for east and west faces is different, and should not be. I get average shading around 40% for the east face and around 58% for the east face. When I check these averages with the sunpath analysis I get around 50% for both, which is correct. Can anyone at sq1 confirm if this is a bug?
Shading Masks
Hello Francisco,
yes you are correct...i have done a quick check on the shading masks..I get 51.5% shade (annual) on the East and 50.2% on the west, but the difference in radiation is almost 25% for me (different weather file in Spain). I don't know what i am missing here.
I have ran the sim in 5.2 and get similar results.
Diffused radiation seems fairly identical for both side, but direct radiation varies quite a bit.
Olivier
Hi Olivier, it looks like a
Hi Olivier,
it looks like a bug In Ecotect. It gets shading masks wrong when calculating solar exposure, but does it right if you look in Sunpath diagrams. Have a look at the excel file I am attaching, and look for the shading averages for east and west faces.
I wish someone at Sq1 would confirm this.
squ1 anyone??
About a month now and no signs frm squ1 (sigh). I would really appreciate some info about this problem, if this is a bug, if it will be solved in the next release...
Please squ1 give users some support!!
Solar Access analysis and Weather data
Hello, I sent this question to Square one before but haven't heard back, and saw this thread. Seems like my question would be somewhat relevatnt here. I really appreciate it if I can get your feed back on my question. Basically how Ecotect converts the weather file solar radiation file into available solar access data.
Thank you,
Koj
I'm trying to use "Solar Access Analysis" tool to see the insolation of a surface and compare with its WEA value. As I understand it, the beam isonaltion data in WEA file is Direct Normal Insolation figure. If so, isn't the value generated by the tool on the sufrace that was oriented towards sun supposed to match the sum of Direct and Diffuse insolation data of that hour in the WEA file?
I'm testing this as follows.
1. create 1m x 1m x 1m box with Zone tool.
2. Pick a date and time.
3. Under "object Transforamtion" tab, align with sun.
4. Run, "Incident Solar Radiation" , initially "Current Date and Time" and changed to "For Current Day"and "Ave.Hourly Values" and specify One hour at the last wind, since the formar option was producing "0",zero.value.
In the WEA, supposedly there are 387w/m2 and 252w/m2 listed as direct and diffuse respectively during that one hour, yet the surface facing the sun is showing 381 w/m2.
Am I doing something wrong or misunderstanding the WEA file format? There is a "cloud" item showing "99" during the hour, does this have something to do with this matter? If so, what equation, or sky model does Ecotect use to come up with its Solar access availability?
Also, is there a way to isolate Beam and Diffuse components in the Solar Access Analysis?
Please advise as I would like to understand the program better.
Thank you,
Koj
No response from SQU1 and
No response from SQU1 and this thread is originally 6 months old. What is going on here? If people are designing buildings based upon data provided by Ecotect, then this could be a worrying situation. A full response from Andrew or one of the "support" team is needed!