Roof_albedo and roof_veg components in DF Edit Typology Envelope are not working!

Hi,

I am trying to understand the effect of roof vegetation and roof albedo on urban heat island, and in my model, I used “DF Edit Typology Envelope” component to change the albedo and vegetation ratio of the roof. However, when I change the values between 0 and 1, urban_epw file did not differ with the cases, and I could not see the added values for roof_alb and roof_veg at typology panel.

Is this a bug?

And, how can I add green roof and cool roof to my urban heat model?

Thanks in advance.

It’s not a bug. You can find more info by reading this post and the following…

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Hi @Francesco661,

Thank you for your answer.

I run the simulation by changing the albedo and vegetation ratio, but there was literally no change in hourly dry bulb temperature values.

EPA suggests installation of green and white roofs to reduce heat island effect, and I would expect to see even a tiny change in epw results, however, there was nothing.

Is this an expected result or did I make something wrong in the model?

The albedo seems to have a scarce incidence on the DBT of the urban canopy layer with DF/UWG.
The grass coverage seems to have more impact than trees coverage. In relation to this aspect, there is an issue opened on the github repository.
Only the geometry of the UCL seems to have a relevant impact on DF/UWG model.