hi @chris,
Thanks again for your response to my question. I’ve tried recreating the deconstructed microclimate map. However, I saw that this workflow is used to calculate MRT for an indoor situation. I’ve altered the workflow by adding a sphere, and giving this sphere a certain long-wave sky temperature Tsky. For the calculation of the long-wave based MRT, I then calculated the sky view factors (with the sphere) and multiplied these by the sky temperature. (see attached file)test MRT LB HB.gh (673.9 KB)
Now I do have a question about the calculation of the sky temperature. In the paper “Wind, Sun, Surface temperature, and Heat Island: Critical Variables for High-Resolution Outdoor Thermal Comfort”, the Tsky should be calculated according to the following formula:
However, when calculating Tsky this way, I get a very large value, which doesn’t make really make sense to me (see figure below). From several sources I’ve learned that the Tsky values should be within a range of -50 and +20 degrees Celsius (https://www.designingbuildings.co.uk/wiki/Sky_temperature#:~:text=The%20temperature%20in%20outer%20space,increasing%20the%20effective%20sky%20temperature.)
From another source (“The Significance of Sky Temperature in the Assessment of the Thermal Performance of Buildings”), I’ve found the following formula to calculate Tsky:
Tsky = (horizontal_IR / sigma)^0.25 – 273.15
With this formula I get a much more sensible result (see figure below).
Do you know whether I do something wrong when applying the first formula?
Thanks in advance for your help!