IES luminaires in Honeybee [+]

I am trying to run an annual daylight simulation in Honeybee [+] including some solar tubes.

Whithin Honeybee Legacy I am familiar with the workflow using IES files to simulate the tubes.
This can be done by creating an additional radiance file and adding it to the additionalRadFiles input of the RunDaylightSimulation component.
In my previous experiences this method works quite well.
However, I would really prefer to use HB [+] over HB Legacy because it is so much faster.

I was wondering why this input for additional radiance files is not available in HB [+]?
Or would it perhaps be possible to add IES luminaires to a HB [+] simulation another way?

Any other advice on modelling solar tubes using HB[+] is appriciated as well.
Many thanks in advance

The below workflow should work, although I doubt if you will see any performance improvements within the context of point-in-time simulations with Honeybee[+].

Using single IES files to represent lightubes within annual simulations does not make a whole lot of sense as the output from the IES file will not change in sync with the changing daylighting conditions.


Hey Sarith,

Thanks for your response. I will test this approach for a Point in time simulation.
This reply answers my original question.

After doing some more research I found that using a BSDF material in a better solution for annual simulations. I also read this valuable discussion:

However, after setting up the workflow, the results seemed much lower than expected. In order to increase insight, I made a comparison with the same geometry, but changing the BDSF material to a glazing material. I would expect the solar tubes to give better illumination performance compared to same-sized skylights, but the simulations indicate otherwise:

In this example workflow, the size of the solartubes/skylights is based on the Solatube XML file (width = 0.60960 m) and the roomsize is 10x10x4m. I used the standard EPW file for Amsterdam. All files are included in the zip-archive below: (448.1 KB)

I can’t find any explanation for the solar tubes performing significantly worse compared to the glazing skylights of the same size, but since it is my first time working with BSDF materials I might have missed something.

Any thoughts?
Many thanks in advance



Hi Shane,

Assuming that the BSDF viewer ( is working properly (cc @mostapha just in case) , I think the results that you are getting do make sense. At the incident angles that I randomly checked, the Solatube does not let in more than 30% of the radiation. Considering that the solatube is usually mounted on the ceiling and right in the field of view of a typical observer, it makes sense that it lets in lesser radiation than a 60% glazing.


Hi Sarith,

Thanks for your reply. I did not know about the BSDF viewer, quite a usefull tool.
This indeed clarifies the results I was getting

Hi @Shane,

Did you find a solution to simulate solar tubes?