What is the impact of Solar Gain on Net Heating or Cooling Required?

Kjell Anderson - February 02, 2021

Medium span (30 seconds)

What is the impact of Solar Gain on Net Heating or Cooling Required?

What is this graphic showing? Describe the different parts of the graphic and how it communicates the data.

Early in design for a complex project in a cold, sunny climate, knowing when solar gain is desired - and how much - can inform basic massing strategies, window to wall ratio, and shading. This chart takes a single-zone shoebox model at various orientations, and compares the heat loss through the facade to solar gain as a ratio of daily solar energy to sf of floor area. It assumes a thermally massy interior that can perfectly capture solar gain as well as other assumptions. Given that weather varies significantly, this provides average enough conditions that each window can be compared to the chart's goals to determine the approximate desire for solar gain.


  • Building Massing
  • Climate Analysis
  • Facade performance (U Value/SHGC/etc)
  • Window shading/sun control

Is this part of the ASHRAE-209 cycle?

  • Cycle 1 Simple Box Model

What tools were used for the simulation analysis?

  • Excel

What tools did you use to create the graphic?

  • Adobe Illustrator

What was successful and/or unique about the graphic in how it communicates information?

Designs, especially orientation, window to wall ratio, and fixed shading, need to reflect average conditions since they will operate through many years with daily fluctuations. Finding the general desirability of solar gain and shading is one of the most fundamental questions but often we don't present design teams with this kind of data.

Is there anything else you would like to mention?

Included in the competition:

Solar Shading and Building Performance
Solar Shading and Building Performance

January 7, 2021-February 8, 2021