HB v/s Autodesk Vasari Radiation test

Hello guys.

Just to understant and compare results I did a test (solar radiation) in HB and Autodesk Vasasri. And I get two different results (both models have the same dimensions ) botjh files are using similar weather data (similar beacause autodesk does not seams to communicate with EP weather stations, they are different weather stations). Bothe files are on winter solstice northen hemisphere (21 decembre at noon)

Any how:

HB gives me a maximum of 74.42 KWh/sq m,

While Vasari returns a maximum of 0.1 KWH/ sq m

what is the difference here?

Any ideas or explanation

Hi Claudio. The units of Ladybug is wrong in this case and it should be Wh/m2 in this case. We already know about this and it is an easy fix: https://github.com/mostaphaRoudsari/ladybug/issues/62. The result is 0.07442 which will be equal to 0.1 if you round the value.

This is fixed!

Hi Mostapha,

I’ve updated LB and HB using the update component. And run the radiation test again. the legend seams correct now for a HOY. But the results still wrong (74.43 Wh/m2)

am I doing something wrong?

thank you


Hi Claudio,

74.43 Wh/m2 looks right to me. If you convert it to KWh/2 it will be 0.0744 which is equal to 0.1 if you round the number. What do you expect the result to be?

Also two points to keep in mind:

  1. As you already mentioned weather files are not the same.

  2. Vasari’s results is not validated so if you want to compare the results I suggest you to compare Ladybug’s result to Honeybee (RADIANCE). Claudio has already done a comparative analysis if you are interested: (http://www.grasshopper3d.com/group/ladybug/forum/topics/data-reliab…).


Yes mostapha, my mistake I did not convert to khw/m2 before posting. I though I deleted the post once I’ve notice my mistake. Also I used vasari because revit is very present in the office. So I wanted to see if I was getting similar results
thank you for the link if Claudio’s post very interesting


No problem. So if we ever get Ladybug for Dynamo started you/your office will be interested in the development.


regarding dynamo and revit yes we will be very interested. This being said personally I prefer GH instead its much more versatile and rino is more suitable, for us, as a conceptual modeler. But here in north America we are forced to breath in a AutoDesk ecosystem.

looking forward to see LB AND HB in dynamo

thank you