Mean Radiant Temperature Estimations

[benterich]

Is your feature request related to a problem? Please describe.
Not really a problem, just something I would find useful. There are various ways to estimate Mean Radiant Temperature, hence it would be useful to have it in this package.

Describe the solution you'd like
One method that can estimate Mean Radiant Temperature. For example the "traditional method" by Fanger, "Six-directional method", "Black globe thermometer method".

Preferably I would propose, one MeanRadiantTemperature Class, that holds the various methods and its inputs.

Describe alternatives you've considered
Otherwise, its also possible to create seperate methods for each estimation independantly.

I can inccoperate them :)!

[FedericoTartarini]

I completely agree that it would be nice to have equations to estimate the mean radiant temperature.

There is already one function that allows you to do that, it is called solar_gain_on_people. The name for this function is not great and we could consider a better naming convention. Moreover, the function to calculate the MRT from the globe temperature is also there already.

I agree that we should have one class/funcition and then people can choose the method they use. Please note that, I am in the process of updating all the function in pythermalcomfort, you can see how I am structuring them by looking at the development branch. I have not updated all the function yet, but you can have a look at the adaptive ASHRAE function.

It would also be very useful to incorporate a function that estimates mean radiant temperature based on the solar radiant, cloud coverage. The authors of the Clima App, have already done that and they have described the method in this paper.

Could you please help me find all the functions we can use to calculate the mean radiant temperature and then we can have a quick call in which we discuss how we are going to add them to pythermalcomfort?

[benterich]

Yes, i would love to help out!

I saw how you updated the functions and it seems clear to me. I am gonna have a look at the estimation done in the ClimaApp and gonna collect all to me known methods to estimate MRT. Then I can make a quick concept which we can dicsuss, ideal would be after the 2nd December, since then i have conducted my masterthesis defense.

Kind regards,
Ben

[FedericoTartarini]

Great to hear that my new code makes sense. As you can see it is not finished but I am planning to work on it as soon as I get back to Australia.

Yes, after the 2nd of December works perfectly since I will be travelling until the 3rd of December. All the best with your oral defence.

I think it is going to be fantastic if we collate all the code to calculate the MRT and include all these functions in pythermalcomfort. Matzarakis Andreas also did some work on this topic and there are applications like RayMan to do the calculations. Perhaps there are also some review papers that they discuss this topic, if there is not perhaps we could consider writing one once you have collated all the functions. :)

[FedericoTartarini]

@benterich Another article that is relevant is this which compares the different equations used by different tools to calculate the mean radiant temperature.

However, it should be noted that with pythermalcomfort we will not be able to calculate all the view factors and surface temperatures of the surrounding objects. We will need to make several assumption, for example, that the temperature of the surrounding surfaces is equal to the air temperature and the sky is absorbing heat from the human body. I have not read in detail the paper from the ClimApp but that should be a good starting point.

[benterich]

"we will not be able to calculate all the view factors and surface temperatures of the surrounding objects. We will need to make several assumption" - Yes i agree, we definitly have to, otherwise we basically building an engine. However, if we provide some smart and carefully though inputs, i think there might be potential to to adpat pythermalcomfort methods to more complicated calculations if necessary or integrate it into other workflows.

So far after some quick searches, beside various Softwares stating how they estimate, I havent found many papers discussion the various techniques to estimate mean radiant temperature, there are many that only calibrate measurement techniques, comparing it sometimes to various computed models.

I think, I try to work out some sort of mindmap with the various functions and correlations and their inputs. From there it should be good to built upon our functions.