Hours of Sun studies
I touched on this in the latest BPA Blog post on the new LAR release, and I'll go into a little more detail here:
Yes, it's possible and fairly easy with Lighting Analysis for Revit to do a study to determine the minimum hours of sun for a target day by Room using the new Custom analysis type. It's not completely automated, but can be done in only 4 analysis iterations and an Excel import of the Schedules. Since glass and materiality is not immportant for solar access, using default materials and glazing is fine, for for most models the process should only take an hour or so from the standard design Revit model.
A few things to note that may be relevant here:
a. Analysis points results are saved with your model.
b. When a new analysis is run, the new points results overwrite the existing saved points results.
c. You can Generate Results on stored points many times without rerunning the analysis. Changing rooms or room parameters, creating new views or sheets, and anything else but changing geometry or materials or analysis times will not affect the stored points results, and you can reGenerate Results from those points any time.
d. The model state in the '_Lighting Analysis Model View', other than Sun Settings, is what is used in the analysis.
e. Generate Results will
- process points to the Schedule per the Thresholds settings,
- generate Analysis Display for Rooms marked 'Include in Daylighting' in the '_Lighting Analysis Floor Plans' and
- generate Analysis Display for all Floors in the currently active 3d view. To generate results in multiple 3d views, make each view active and click Generate Results again for each.
f. If using Linked model geometry such as shell and interiors, etc, not all aspects of linked models are handled automatically.
- Analysis grids are generated from Floor objects in the main model, so floors cannot be in a linked model. Bind or import them to the main model.
- Rooms must be in the main model as well to be recognized for schedules and floor plan display. Rooms must also be bounded and not just markers, so make linked geometry Room Bounding when creating Rooms.
g. If using copied groups that contain Floor objects, you must allow them to be ungrouped when Generate Results, as the results are associated uniquely with each floor.
h. Since you have a fairly large model and you will need to run 4 analysis iterations, it would be worth making sure that you only include Floors that you need. All Floor objects associated with Levels selected in Run Analysis will generate analysis grids. Any floors that you don't want to include, such as outside surfaces, miscellaneous floor objects used as shades or other surfaces, etc, should be moved to a separate Level that will not be selected for Analysis.
Here is the workflow I would suggest:
1. (opt) Open your model Detached from Central. The reason for this is so you can save the 4 batches of analysis results for later reference and documentation. This is good practice anyway so that the results are always up to date with the current model.
2. Set up the basic settings:
- Set location using Manage > Location > Internet Mapping Service, and be sure to choose a weather station from the list beside the map. The closest one automatically selected is fine.
- Create Rooms and set the Living Rooms and Private Open Spaces with Include in Daylighting checked. If that parameter is not yet available, click Run Analysis, then cancel so LAR can set up your model with the required views and shared parameters.
- Create an Analysis Display Style in Manage > Settings panel > Additional Settings drop-down > (Analysis Display Styles). Create a new one named 'Lighting Analysis - Solar Access' of type 'Colored Surface' and set the Color settings to have 2 values between Min and Max. Set the Min color to gray, set the next value to 4000 and gray, set the next value to 4001 and yellow, and set the Max color to yellow. This will display areas of direct sun in yellow and the rest in gray.
3. Save the model (if detached from central) with a name appended with something like '...DirectSun_09-10am'. Do this 4 times to cover 7 hours (9am-3pm), 2 hours at a time so you will have 4 versions of the same project file.
4. Click Run Analysis, choose the Custom analysis type, and set the Environment Settings Date/Times to your mid-winter day, and time1 to 9am, time2 to 10am.
5. To run an analysis with only direct solar, uncheck 'Use Weather Data' and set the DNI Solar Data value set to 1000 and the DHI Solar Data value set to 1 (minimum). The GHI Solar Data value won’t have an influence on the Perez sky model, so it can be set to 1000 as well. Do this for both times.
6. In the Illuminance Settings, set the Lower Threshold value to 4000 Lux (to capture very low angle direct sun, but not reflected sunlight in a space) and the Upper Threshold value to 130,000 Lux (just above 1000 W/m2 on a surface normal to the direct sun). Set the Analysis Plane Height to 1 (minimum) to capture sun on the floor, or another height as desired.
7. Click Start Analysis. When the notification shows that the model has been uploaded, Save the Revit project.
8. Open each of the other 3 files for the other hours and set the date and times to those hours with the same Solar Data settings in step 5. Continue with steps 6 and 7 for each, saving each file when the model is successfully uploaded. If your model is large you can do this one at a time, closing in between; the analysis results will be reconnected when you open the model again later. Analysis may take 1 minute to 20 minutes depending on the model size, and they can be run concurrently so the whole process should take less than an hour or so.
9. When each model analysis is running, open the first one and you will either get a message that the analysis is complete, or you can click Run Analysis again to check the progress.
10. When analysis is complete, click Generate Results. This will give you
- Floor plan views with the Living Rooms and Private Open Spaces showing direct sun in yellow. To view each of the analysis times, click on the colored surface (Analysis Results object) and view its properties. Select the 'Analysis Configuration' for the time you want to see. Choose the Analysis Display Style you created earlier.
- Room Schedule with the percentage of area in each Room that is 'within threshold' being the area that has direct sun. If the Room has 0% within and above threshold, and 100% below threshold, that Room has no direct sun access for that hour.
- If in a 3d view when Generate Results is clicked, you will see results for all Floors. You can turn on and off Levels in the Analysis Display Settings properties.
11. To get a solution for how many hours of direct sun each space has for the 7 hours, select the Room Schedule and export it using Revit menu > Export > Reports > Schedule for each of the 4 analysis iterations, then combine the results in Excel to summarize the number of hours each Room has Threshold values within or above thresholds. Hours that have no direct sun access will have 100% of the space 'below threshold'. Attached here is an Excel template that will do the calcs for you. Import the Schedule txt file export into each of the tabs and the last tab should give you the results you are looking for.
Hi,
i checked Insight for Revit 2018.
I have to prove that apartments in a building receive direct sunlight (direct rays from sun to apartment).
Insight give me wired result. How can I have in north room direct light from sun?
Maybe is better tool to calculate and access a large project in revit (maybe something in Dynamo)?
Thanks in advance.
