topic Re: Daylight Factor Analysis using Revit 2016 in Lighting & Solar Analysis Forum

Daylight Factor Analysis using Revit 2016

Anonymous — Fri, 29 Jan 2016 11:54:22 GMT

Hello,

I am trying to run a Daylight Factor analysis using revit's "Render in Cloud" function and I would like to know if it's somehow possible to get a numeric grid besides the graphical plan, something like the picuture from Ecotech I attached

Thanks in advanced,
Hassib

Re: Daylight Factor Analysis using Revit 2016

scheerd — Mon, 01 Feb 2016 16:05:46 GMT

Hello.

Yes indeed. Daylight Factor sky model is now available through Lighting Analysis for Revit.

1. Select a Custom analysis type and set the analysis plane, thresholds and levels settings as you like, then

2. Create an Analysis Display Style that looks something like the attached, using your desired thresholds for break points. Alternatively, use the 'Lighting Analysis Default' display style to show the full range.

FYI, the analysis times and solar settings are not used when doing a daylight factor sky, as the sky is automatically set for a 0-100 lux illuminance on horizontal surfaces in full sun, so that the 'lux' values are a proxy for daylight factor.

David

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Tue, 02 Feb 2016 08:28:10 GMT

Hello David

Thank you for replaying, this was very useful

have a nice day,

Hassib

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Thu, 22 Dec 2016 08:01:38 GMT

In daylight factor sky condition, is there anyway to set the acceptance threshold in the form of decimal points?

Thank you

Re: Daylight Factor Analysis using Revit 2016

stephanie.egger — Tue, 03 Jan 2017 22:28:36 GMT

Hi @Anonymous,

Unfortunately you must use a whole number for specifying threshold criteria.

I'm curious, what values are you trying to simulate with decimals?

You could always just change the Analysis Display Style legend, and enter decimal points there for more specific values.

-Stephanie

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Wed, 04 Jan 2017 00:34:27 GMT

Hi Stephanie.

Local standards in Malaysia defines DF of 1-3.5 as acceptable threshold for daylight harvesting.

Setting the Analysis Display Style legend will be able to show the coverage area, however would prefer if it can be specified threshold criteria, so that we can report on the area coverage.

Thanks.

Re: Daylight Factor Analysis using Revit 2016

stephanie.egger — Wed, 01 Feb 2017 01:35:29 GMT

@Anonymous,

Good to know. Right now your best bet would be to manipulate the analysis display settings. You could also view the analysis as points with annotations and visualize the values with decimal places there.

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Tue, 16 May 2017 09:50:55 GMT

Hi,

I am just wondering if Daylight factor analysis is still available, because I can not find it in this list. I am using insight 360 for Revit 2017.1.

Kind regards,

Anahita

Re: Daylight Factor Analysis using Revit 2016

rds3000 — Fri, 26 May 2017 23:01:36 GMT

Hi there.

The Daylight Factor style is something you'd have to create yourself in the Analysis Display Styles, which you can get to from the 'Graphics' section of the properties for a view. The example I gave earlier was of a style I had created myself. Since DF regulations are so different around the world, we chose to not include a stock one in the LAR install.

The DF analysis method is indeed still available through a Custom analysis type (in the new release this is called the 'Illuminance' analysis type), where you can select the 'Daylight Factor' type from the Sky Model type. Remember, the results from this analysis type have smaller numbers than any of the other analysis types, so you'll have to create a style to view the results, as the other styles all are based on much larger Illuminance Lux values.

David

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Mon, 17 Jul 2017 21:05:56 GMT

Perhaps someone can clarify. I am trying to get a model where the points on the floor plan show a daylight factor (2%, 5% etc), similar to the sefaira analysis view.

if i choose daylight factor sky, the key in my analysis plan appears to still be giving readings in lux, not percentages as the guidance would suggest.

help!

Re: Daylight Factor Analysis using Revit 2016

scheerd — Thu, 20 Jul 2017 01:44:15 GMT

Hi all.

This is a bit of a wonky answer, but I hope it helps.

We added the DF sky model option as a bonus feature without the full automation of units and styles on the other analysis types. This is because we could do it easily if we lumped it in with the other custom Illuminance analysis settings, and it's not an analysis that's used much these days.

Since we lumped the DF sky model into the processing stream of analyses using other sky models, which all yield results in Lux, the numbers are correct for the DF sky run, and are % (0-100), but the display units shown in the style don't correspond to the units of the data for this case only.

On the back end, the 'units' of Lux or FC are applied just for labeling and conversion (like from 'lux' to 'fc') when we add the points values to the Analysis Display (AVF) in a view. The AVF tool doesn't allow multiple 'schema' with different labels in the same results, so we just lumped the results from a Daylight Factor sky into the framework we use for the regular Illuminance results, which are all in Lux with a conversion factor for FC.

Bottom line is that the native units when using a DF sky are % (0-100), and the scale will show properly (though with the wrong label of 'lux') if you have the 'units' set to 'LUX'.

Attached is an image of the settings I use (click on the Analysis Results to access these properties panel, or just accept the default and set up a new analysis display style with values for whole-percent). You can see in the highlighted range that the values make sense for the 0-100 range.

Thanks for the patience on this one!

David

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Wed, 23 Aug 2017 09:35:33 GMT

Hi there,

Is it possible to calculate an average Daylight Factor per room rather than looking at a spectrum of values (in my model ranging between 1-14 %)?

Re: Daylight Factor Analysis using Revit 2016

mstein7484 — Thu, 24 Aug 2017 22:55:17 GMT

Hi @Anonymous

The tool doesn't report room averages, but you might be able to make a rough estimate based upon the thresholds shown in the 2D view.

Regards,

Re: Daylight Factor Analysis using Revit 2016

rds3000 — Fri, 25 Aug 2017 05:43:37 GMT

Like Margie said, the visual way of doing it is to make an Analysis Display
Style with one color up to your average threshold, and a second color below
that threshold (fyi check the points values with a 'points_anno' style to
make sure your threshold is inclusive of the value you want), then either
estimate or sketch a shape at the boundary to measure the successful area.

You can also export your results to Excel using the setting in the Settings
panel, currently on the Run New Analysis dialog. This will open raw
results in Excel. Careful, it could be a large file. Also it is not
organized by Room, so you'll need to play a bit to configure your model or
the results to parse the values to aggregate.

Custom analyses like this are really best done with Dynamo, where you can
process results points by any custom aggregation or threshold.

BTW, where are you located (what jurisdiction) that Daylight Factor is used
as a performance metric? It's not a very good metric for daylighting
performance, and generally it was used because tools were not able to
calculation illuminance. You might be able to use one of the more advanced
metrics if your jurisdiction has an option for another performance metric.

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Fri, 01 Sep 2017 16:29:43 GMT

When I'm running the Daylight Analysis, I am getting two sets of numbers ONLY at the first floor. I've check to make sure there aren't two floor assemblies and there are not. Any suggestions??

Re: Daylight Factor Analysis using Revit 2016

scheerd — Fri, 01 Sep 2017 17:06:35 GMT

The reasons we've seen that in the past have been either two floors (usually floors built in layers to represent structural and finish floors) or some linked-in model that may be part of a group with a second floor copy at that elevation, or a ceiling or other object is modeled using a 'Floor' object, and potentially it has an odd offset from the associated Level or something.

LAR groups floor points by Level, so to track this down I'd suggest the following:

1. Copy the _Lighting Analysis Model View, which is where the geometry comes from.

2. Go to Visibility Graphics settings (type 'VG' in the view) and turn off all element types except Floors.

3. Crossing-window select everything in your problem area and see how many objects you have selected.

If all else fails, I'm glad to look at the model if you want to send me a link.

David

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Fri, 01 Sep 2017 18:14:48 GMT

Hello David,

Thank you very much for the reply! I went through to verify there weren't more than one floor. I ended up copying the 2nd floor plate down to the 1st floor since the 2nd floor was appearing correct. When I go back into the "Select Analysis" menu, I select my previous analysis but the numbers remain the same. Will I need to re-run the analysis in order to see if that fixed it? I'm trying to avoid having to pay each time...

-Ryan

Re: Daylight Factor Analysis using Revit 2016

rds3000 — Fri, 01 Sep 2017 18:27:37 GMT

Hi.

Yes, you'll have to rerun the analysis, as the old run will just restore
the original results from the cloud storage.
One thing you could do to save credits is to just run the single level on
low resolution (either Illuminance or LEED2009 will give you the option for
a 6' grid at the lowest cost). If that still is not free or cheap, let me
know, and I can validate the model before you refresh the runs if you don't
mind sending it to me.

David

Re: Daylight Factor Analysis using Revit 2016

Anonymous — Wed, 06 Sep 2017 16:55:14 GMT

Good morning David,
I wanted to check in and see if you had a moment to take a look at the model to see why the multiple measurements were taking place. Thank you again for your assistance on this. I'm hoping to get this credit finalized this week.
Have a good one,
Ryan

Re: Daylight Factor Analysis using Revit 2016

scheerd — Wed, 06 Sep 2017 18:38:01 GMT

Hi Ryan.

Did you send the model? i didn't receive it. Please post a download link here or use my email scheer.3d@gmail.com.

David