An Introduction to Sefaira Daylighting Visualization

Sefaira Daylighting Visualization helps designers make better decisions regarding glazing, shading and facade design. Targeted analysis and downloadable visualizations help designers defend and advocate for design decisions by communicating the potential performance and experience within a space.

This article will help you accomplish the following:

  • Learn how to quickly perform daylighting studies and generate graphics for presentations.
  • Understand how other firms are using Sefaira Daylighting tools to enhance their projects.

Make sure you have downloaded and installed the Sefaira plugin for SketchUp and/or Revit, and that your SketchUp or Revit model is ready for analysis.

Daylighting Visualization Feature Overview

Sefaira conducts annual and point-in-time analyses using Radiance and Daysim engines. Specifically, Sefaira offers five unique analysis visualizations:

  • Date and Time: Assesses location-specific daylighting for a specific hour, day, and month. Assumes a clear sunny sky.
  • Annual: Reports point illuminance values derived from calculating location-specific and climate-specific daylighting over the course of a year.
  • Overlit & Underlit: Uses Annual analysis data and reports areas across the horizontal workplane where there is either too much direct sunlight or where there is adequate daylighting.
  • Daylight Factor: Assumes a uniform cloudy sky, and reports daylighting as a ratio of indoor illuminance to outdoor illuminance.
  • Direct Sunlight: Considers only direct beam solar radiation and illustrates where on the horizontal workplane there is direct sunlight for a user-specified period of time.

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Click one of these five icons to select your desired daylighting analysis.

Sefaira presents results in the Daylighting Visualization window as well as the dashboard dial.

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The dashboard dial provides the following three metrics:

  • Underlit: The percent of floor area where there is not enough daylighting to adequately illuminate the work surface.
  • Well Lit: The percent of floor area where there is enough daylighting to adequately illuminate the work surface.
  • Overlit: The percent of floor area where there is too much direct sunlight, which indicates a risk for increased thermal loads and visual glare.

Analysis Inputs and Settings

The following two inputs are required, regardless of the analysis you are conducting:

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  1. Visible Light Transmittance (VLT): The VLT of window glazing impacts how much visible light enters a space. This setting is applied to all glazing in your project.
  2. Workplane Height: Sefaira conducts sensor-based simulations, meaning it traces rays of light and registers how many hit a given sensor point. The sensor points are laid out in a regular horizontal grid, and are offset vertically from the building floor. Their vertical offset distance is defined by the “Workplane Height” input.

 

In addition to type-specific settings (e.g. Lux threshold for Annual Analysis; month, day, and hour for Date & Time Analysis, etc.), there are a number of general daylighting-related settings to be aware of:

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  1. Units: Choose to view illuminance in Lux or Footcandles, whichever metric you are more familiar with.
  2. Ambient Bounces: Defines how many reflections are considered. For example, a deep room with only one window at the far end might demonstrate low light levels at 2 AB compared to higher light levels at 4 AB as light was allowed to bounce more and thus penetrated deeper into the space. Note that increasing precision also increases analysis time.
  3. Grid Resolution: Defines the spacing of sensors used in the analysis calculation. A High resolution delivers a more tightly-spaced sensor array than a Low resolution. Like Ambient Bounces, though, precision comes with a cost of increased analysis time. You can read more about grid resolution here.

Running Analysis

Now that you’re familiar with the types of analysis Sefaira offers as well as the general inputs and settings that support a simulation, let’s try generating a daylighting visualization.
Open the Sefaira Real Time Analysis plugin.

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Set your analysis mode to “Daylight Analysis” and make sure the Daylighting Visualization window is open.

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Set your your desired use type, location, and baseline (which includes a value for VLT):

Select your desired daylighting analysis by clicking on one of the five options on the left side of the Daylighting Visualization window. Define any analysis-specific settings (e.g. month, day, and hour for Date and Time analysis).

Click “Update Analysis” and wait for the dashboard dial and visualization to update.

Note that the image in the Daylighting Visualization window syncs with your SketchUp or Revit camera. To manipulate the image, use your design tool’s orbit, pan, and zoom functions to position the camera. In Sefaira for Revit, you can also pan and zoom directly in the visualization window itself.

Capturing Daylighting Graphics

After generating a Daylighting Visualization, you may want to capture what you’ve learned.

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Use the camera button (1) to download a snapshot of the visualization window; or, download an orthogonal plan view of the heat map associated with a given floor (2).

Read on to learn more about how you can refine and customize your daylighting visualizations.

Visualization Settings

The annotated screenshot below notes the settings you can apply to any visualization:

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  • Color scheme*
  • Style (Contour, Gradient, or Grid)*: The Grid style can also be used to visualize the sensor spacing that has been applied to your simulation.
  • Context geometry: You can choose to include building elements like walls and windows in order to help contextualize the visualization.
  • Floor list: Choose to show all floors in a visualization or just select floors by toggling their visibility via this list.

*You will need to Update Analysis for the change to take effect.

Case Studies

You are now ready to leverage daylighting analysis in support of your building design decisions. See what other Sefaira users have achieved by doing just that.

Sterner Design: Daylighting an Underground House & Achieving Net Zero Energy Status

Sterner Design used Sefaira to set and achieve Net Zero Energy goals and deliver great daylighting by tracking the impact of design choices on energy and daylight throughout the design process.

Hewitt Case Study: Making Informed Design Decisions with Sefaira

HEWITT used Sefaira to analyse and assess three concepts for a high-rise residential development in Seattle.

A Tactical Approach to Performance-Based Design

Elizabeth Ratner from Little Diversified Architectural Consulting Conducted analyses to inform design decisions that could save the client significant costs over the life of the building.

 

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