What is the impact of a double cavity wall of an office building on occupant thermal comfort?

Graphic Name:

What is the impact of a double cavity wall of an office building on occupant thermal comfort?

Submitted By:

Olivier Brouard

Firm Name:

Skidmore, Owings, and Merrill LLP

Other contributors or acknowledgements (optional):

- Olivier Brouard, Sustainability Engineering Team Leader - Stephen Ray, CFD Engineering Specialist

What tools did you use to create the graphic?

Project Information

What are the primary inputs of the analysis/analyses included in the case study?

Orientation, Location, Weather file, Window-to-wall ratio, Double Glazing, SHGC, Internal heat gains, external solar radiations, HVAC system

What are the primary outputs/metrics of the analysis/analyses included in this case study?

Predicted Mean Vote, Mean Radiant Temperature, surface Temperature

Gross Floor Area of Project Covered by Analysis


ASHRAE Climate Zone


Project Zip Code (optional)

Primary Building/Space Type Covered by Analysis
  • Office
If you selected 'Mixed Use' on the previous question, what are the different uses?


List the investigations questions that drove your analysis process.

How is occupant thermal comfort optimized with a ventilated double wall cavity as compared to a double pane insulated glazing unit system?

Who performed the simulation analysis? (select all that apply)
  • Architect - Internal Sustainability Personnel
What tools were used for the simulation analysis? (select all that apply)
  • EnergyPlus
What phase of the project was analysis conducted? (select all that apply)
  • Design Development
How was simulation integrated into the overall design process?

The tool utilized is not showing in the drop-down menu and is not Energy Plus. Open Foam CFD engine, Helyx gui user interface and Paraview were used to run and visualize the analysis The simulation happened during the end of the DD phase when the design team had to consider double vs triple glazing unit. A double-wall cavity facade was considered to enhance user comfort while reducing energy use through a warm blanket system. The design was integrated collaboratively. Running the timestamp April 26 showing the highest amount of direct beam radiation was used as a worst case scenario. (screenshot below)

How did you set up the simulation analysis and workflow?

The simulation analysis followed the following steps: - highlight the zones of the project - take a typical zoning area and simplify the geometry in rhino - export the rhino model into Helyx - setup the internal, external heat gain from user activity, receptacle, solar radiations, outside and inside temperature, HVAC operative temperature and occupant location neat the perimeter were heat exchanges are the greatest - run open foam computational fluid dynamic software - export results into ParaView to visualize the outputs

How did you visualize the results to the design team? What was successful about the graphics that you used to communicate the data?

The results were visualized over a powerpoint highlighting the major findings

Most importantly, what did you learn from the investigation? How did simulation and its outputs influence the design of the project?

More tools should be listed for Computational Fluid Dynamic software playing a crucial role in transient and steady heat flow condition. Open Foam CFD was used as a back engine, Paraview as a front end interface.

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