Compared lighting analysis

[andreabotti]

I am using IES for an academic research project and I am trying to assess different facade options for a typical office room.
I have come across a useful software developed by Lawrence Berkeley National Laboratory called ComFen (based on energyplus engine) which does exactly that http://windows.lbl.gov/software/comfen/4/Overview.png.
Now, because IES VE is far more versatile and powerful software package the number of variables and controls to set in order to achieve a similar comparative analyses are more time consuming.
However, I am particularly interested in assessing different facade options with regards to daylight levels and energy saving as a result of dimming.
My main doubts are the following:
- there can be inconsistency between the lighting levels within the thermal template (assuming, for a UK scenario, the NCM ref values for office buildings) where under internal gain: max ill 400lux and lightPro template where ill level= 500lux. Which one is to take into consideration? Will Radiance take that into consideration of sensors even if luminaires are not modelled?

- is there any quick way to obtain parametric values for energy consumption for lighting for each dummy room (each with a different shading system)? The following slides show results I obtained by running comparative analyses on passive performance for different shading systems for dummy rooms (sized as a "slice" of the building I am studying)
https://www.dropbox.com/s/8cbrq0um1p5oa4x/Slide1.JPG
https://www.dropbox.com/s/aqezc0bpdn6t0c5/Slide2.JPG
https://www.dropbox.com/s/kkv52f765p9nnle/Slide3.JPG
https://www.dropbox.com/s/wc9rlgboyuidi8z/Slide4.JPG
https://www.dropbox.com/s/gfdefiizvlgq3ft/Slide5.JPG


Thanks,
Andrea

[Complex Potential]

For this sort of analysis you should be using a combination of radiance and apachesim. I'd ignore the NCM templates and simply create your own.

You can up sensors for your rooms within radiance and run the design day calculation which can then be imported to apachesim (there is a check box for radiance as you go to run a dynamic thermal model).

However, before you run apachesim you need to set up a dimming profile and apply it to your lighting gain within the space, referencing the sensors, so that the program knows how you want to dim the lights and what the target illuminance in the space needs to be.

I think the apache help pdf has some examples of profiles for linking to radiance sensors and auto dimming the lights.

CP

[andreabotti]

Mr CP,
thank you for your reply.
I am familiar with setting up a dimming profile having done it in the past. What I am not sure of is what in the LightPro tab (within the building template manager) is taken into account.
Also I am not entirely sure why within the sensors tab (RadianceIES module) separate simulations are available for radiance and apache.

Thanks,
Andrea

[Complex Potential]

Both good questions and I'm afraid I can't answer either of them. I've never used LightPro and I've never found a use for the "Radiance" button within the sensor tab.

[andreabotti]

Does anyone have a better understanding on this?
Also, I assume that any assumption on glazing properties set in Apache would not be "read" by Radiance. I am referring in particular to visible light transmission Tvis: if I set that in Apache, do I need then to set it separately in Radiance for the light sensor within the room to read it?

Thanks,
Andrea