Abnormally high shortwave radiation values

All around LEONARDO 4 (and previous 2014)
BGovehovitch
Posts: 27
Joined: Mon Mar 12, 2018 9:30 am

Abnormally high shortwave radiation values

Postby BGovehovitch » Wed Jan 08, 2020 11:06 am

Hi ENVI-met team!

First of all, I would like to wish you a happy new year!

I encounter problems with the shortwave radiation values. I use a really simple model to investigate on it.
In the forcing manager, the solar irradiation looks like this:
forcing_sw.PNG


But the shortwave received at façade is much higher. For example, the result at 9:00am:
received_sw.PNG


There being no reflection nor shade on the roof, I should have the same value in the result than the one in the forcing. But I get much higher value, which is physically impossible. What do I do wrong?

Thank you for your help.

Benjamin

Tim
Posts: 1210
Joined: Mon May 15, 2017 3:46 pm

Re: Abnormally high shortwave radiation values

Postby Tim » Wed Jan 08, 2020 11:30 am

Hi Benjamin,

Please check, whether the parameter "Radiation measured on horizontal surface?" for the CSV import was set correctly.

Best regards,
Tim

BGovehovitch
Posts: 27
Joined: Mon Mar 12, 2018 9:30 am

Re: Abnormally high shortwave radiation values

Postby BGovehovitch » Wed Jan 08, 2020 3:49 pm

I checked twice, and the "Radiation measured on horizontal surface?" parameter is checked. It is confirmed by the value of the tag radSurface in the fox file. The value is horizontal , and not lambert.
I ran the simulation once again, after verification, and I still get more than 900 W/m² on the roof.

Tim
Posts: 1210
Joined: Mon May 15, 2017 3:46 pm

Re: Abnormally high shortwave radiation values

Postby Tim » Wed Jan 08, 2020 6:03 pm

Hi,

If you checked horizontal, the values are recalculated during the simulation.

How do the values look like, if you uncheck the button?

Best regards,
Tim

BGovehovitch
Posts: 27
Joined: Mon Mar 12, 2018 9:30 am

Re: Abnormally high shortwave radiation values

Postby BGovehovitch » Thu Jan 09, 2020 9:57 am

Hi Tim,

The result is exactly the same if I uncheck the horizontal parameter. I really don't get it.

Benjamin

Tim
Posts: 1210
Joined: Mon May 15, 2017 3:46 pm

Re: Abnormally high shortwave radiation values

Postby Tim » Thu Jan 09, 2020 10:44 am

Hi Benjamin,

Could you upload the files, so that I can test with them?

Best regards,
Tim

BGovehovitch
Posts: 27
Joined: Mon Mar 12, 2018 9:30 am

Re: Abnormally high shortwave radiation values

Postby BGovehovitch » Thu Jan 09, 2020 12:21 pm

Tim,
Here are the file for both both horizontal and not horizontal radiation measurements:
debug_sw.zip
(316.76 KiB) Downloaded 3 times


Thank you for your help,
Benjamin

Tim
Posts: 1210
Joined: Mon May 15, 2017 3:46 pm

Re: Abnormally high shortwave radiation values

Postby Tim » Thu Jan 09, 2020 1:52 pm

Hi Benjamin,

Unfortunately, we found a bug there. The correct option would be lambert but this option is overwritten during a debug routine in the simulation. We will upload a fixed version within the next weeks with some additional fixes. In the meantime, you should be able to run the simulation correctly with a workaround: Replace the tag <dataSrc> measured </dataSrc> with the tag <dataSrc> EPW </dataSrc> in a text editor such as Notepad++. The lambert setting is then not overwritten and the radiation values are kept as they are. Sorry for the inconvenience!

Best regards,
Tim

BGovehovitch
Posts: 27
Joined: Mon Mar 12, 2018 9:30 am

Re: Abnormally high shortwave radiation values

Postby BGovehovitch » Thu Jan 09, 2020 4:03 pm

Hi Tim,

Thank you very much for your help and the workaround. It looks as if it is doing very well.
I am waiting for the fixed version but so far, I should be able to run my simulations.

Kind regards,
Benjamin


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