How to get irradiance values(W) on the manikin with Honeybee[+]?

Hello everyone! I’m a university student in Japan and studying multi-node thermal comfort models.

I read the two materials, “A new modeling approach for the assessment of the effect of solar radiation on indoor thermal comfort” written by Andrea Zani and “Employing Radiance in Thermal Comfort Simulations involving Complex Fenestrations” written by Sarith Subramaniam, and was very impressed!
So I’m trying to get irradiance values (W) on each parts of the body.

I have a question about that.
Can I get irradiance values(W) using only Honeybee[+] DC Grid-based Daylight Recipe component without additional Python or Radiance source code?

Your help would be much appreciated.

Sincerely, Yuta

The DC grid-based recipe calculates illuminance by default. So, you’d have to change a few things in the final .bat file that is written out by Honeybee[+] (mostly disabling the conversion from irradiance values to illuminance).
I think other than that, it should work provided that you are only considering direct radiation from sun and sky to the manikin. Values for reflectance typically tend to be assigned for lighting calculations, so any consideration of that in thermal comfort simulations is likely to be incorrect.

Regards,
Sarith

@sarith
Thank you very much for the reply. It was very helpful!
If you don’t mind, there are two more thing I’d like to ask you.

1.What is the unit of irradiance obtained from DC method results?
In the DC grid-based recipe, the unit is expressed in solar energy [kwh/m2], while in the two materials I read, the unit is expressed in peek power[W/m2](epw file data includes irradiance value [Wh/m2]). I need the peek power [W/m2] to determine thermal comfort.

2.Is it suitable to use the DC grid-based recipe in outdoor?
I got results of irradiance values in outdoor, but some values became so high when I changed final .bat file. Please let me know if my flaw of the convertion is obvious.

here is .gh and .bat file;
https://drive.google.com/drive/folders/1mj7nmFLDycIUv6yN7ukHzf514WpV8UaD?usp=sharing

I really appreciate your kindness and sorry for my bad English.

Yuta

The unit of illuminance, which is what the DC script calculates, is lux (or lumens per sq. m). The weighting factors c:\radiance\bin\rmtxop -c 47.4 119.9 11.6 are used to convert Watts/sq. m to lumens/sq. m. So, to answer your query…

… the units are in Watts/sq. m (If remember this correctly!).

Regarding this…

… I think it is fine to use the recipe outdoor. The higher values are likely because there is no shading occurring.

By the way, the commands that begin with echo are just comments and have no bearing on the simulation. So, you need not bother changing anything here:
echo :: :: rmtxop -c 0.33 0.33 0.34 [results.rgb] ^> [total results.ill]
Is there a reason that you have bumped up the blue channel to 0.34 (instead of 0.33). It might be better to set each of the values to 0.333333 instead of having a slight imbalance in one of the channels. It is unlikely to matter much anyway.

Regards,
Sarith

1 Like

@sarith
Thank you so much for your answering and advice! It was very helpful.

Thanks again,
Yuta