Issue with Mean Radiant Temperature

Post here for very basic questions and request for help...
But: BEFORE you post, read the older posts if your question hasn't been answered before.
Please be specific. Q like "I don't understand ENVI-met" will most likely be ignored.
Post Reply
nathphil
Posts: 22
Joined: Wed Oct 02, 2019 7:58 am

Issue with Mean Radiant Temperature

Post by nathphil »

Hi ENVI-Met team,

I've started to analyze the results concerning the different parameters of the atmosphere files. However, the Mean Radiant Temperature presents some irrelevant values. The highest value is actually of more than 150°C at 7:00 am. Nevertheless, the potential air temperature and relative humidity values are very closed to measured values.

Here are the EDX and EDT atmosphere output files.

https://we.tl/t-BZXYTKqBP6

And here my full forcing file.

https://we.tl/t-dPNXtDl9KH

Thank you in advance for your reply and sorry for the inconvenience.

Best,

Nathalia

Tim
Posts: 1668
Joined: Mon May 15, 2017 3:46 pm

Re: Issue with Mean Radiant Temperature

Post by Tim »

Hi Nathalia,

If you have a look at the radiation values, you will see the reason for it. The direct radiation values are much too high. You have radiation values which are measured or calculated to be perpendicular to a surface. When importing the CSV in order to get the FullForcing File you need to uncheck the box "Radiation measured on horizontal surface". If it is checked, values are recalculated during the simulation and thus get too high, especially if the sun angle is low.

Best regards,
Tim

nathphil
Posts: 22
Joined: Wed Oct 02, 2019 7:58 am

Re: Issue with Mean Radiant Temperature

Post by nathphil »

Hi ENVI-Met team,

Please allow me to speak again on the previous topic.

I followed your advice and unchecked the box ""Radiation measured on horizontal surface" during a new simulation for another day. Since we have two PC, we've chosen to run two simulations with exactly the same characteristics, excepted this option (we've checked the box in the first simulation and unchecked it in the second). Despite this difference, the both simulations present exactly the same results concerning the Mean Radiant Temperature.

Moreover, the values of the MRT are excessively high during the morning, whereas they seem to be more consistent and logical during the afternoon and after the sunset. The direct radiation values in the full forcing are less high than for the other simulation from this topic. They're come directly from one of our weather stations (horizontal measurement) and concern this particular day.

Here are the Full Forcing file and the EDX and EDT atmosphere output files.

https://we.tl/t-k53HMrFI33

And here the EDX and EDT radiation output files.

https://we.tl/t-wJnvsgO9Vr

Thank you very, very much in advance for your reply.

Best,

Nathalia

Tim
Posts: 1668
Joined: Mon May 15, 2017 3:46 pm

Re: Issue with Mean Radiant Temperature

Post by Tim »

Hi Nathalia,

I think that it is the same issue as I described in this post: http://www.envi-hq.com/viewtopic.php?f= ... b451#p9813.
The tag was probably not read correctly. You may either try the described fix or download the recent version from our homepage where we fixed this bug.

Best regards,
Tim

nathphil
Posts: 22
Joined: Wed Oct 02, 2019 7:58 am

Re: Issue with Mean Radiant Temperature

Post by nathphil »

Hi Tim,

Thank you very much for this fast answer !

Best,

Nathalia

Post Reply