What is the comparative impact of massing and orientation on the energy use of an office tower located in Sydney, Australia?

 

PROJECT INFORMATION

Submitted by:  Olivier Brouard

Firm Name:

What kind of graphic is this? 2d Chart

PROCESS

What are the primary inputs of the analysis that the graphic describes?  

Orientation, Width and Length, Same Gross Floor Area, Same conditioned floor area, Same unconditioned floor area across all schemes

List the primary outputs/metrics that the graphic describes?  

predicted Energy Use Intensity converted into relative % for comparative purposes

What is this graphic showing? 

The graphic shows a heat map reflecting 370 whole building energy modeling simulations following 2 main variables: rotation and variation of the dimensions (length and width) of an office massing, made of 23 floors. Each rotation is incremented by an angle of 5° from 0° north to 180° (shown on the horizontal axis). 10 different aspects ratio is proposed using the same gross square footage for each scheme (shown on the vertical axis). The climatic information shows the sun radiations come from the north in Sydney. The heating and cooling degree map suggest a mild climate where insulation is necessary as much as solar radiation control. Thus the impact of the orientation and aspect ratio of the scheme was the first step to underline where is the fine line between performance and urban site fitting.

How did you make the graphic? 

The graphic was made using Excel after aggregating the pEUI of the output energy runs. A conditional formatting rule is applied to show low to high values.

What tools did you use to create the graphic?

What specific investigation questions led to the production of this graphic?

Understand the impact of the orientation and aspect ratio of the scheme on the overall energy use before optimizing the envelope and addressing the active systems and renewables if applicable.

How does this graphic fit into the larger design investigations and what did you learn from producing the graphic?

This graphic shows the magnitude impact of the climate environmental variables on a building (temperature, solar radiations) and how to best understand bioclimatic design as it relates to low solar angle beam radiations. Shortening the west and east exposure leads to a few % of energy savings as compared to maximizing their exposure to the west and east orientations inducing more cooling penalty.

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

The graphic shows that a compact massing performs better overall by 4.3% as compared to the worst case. The best case was a squarish massing orientated 85/90 degrees north with a side core located to the East to address the low beam solar radiations. The envelope area to volume ratio drives the variable load energy use.

What would you have done differently with the graphic if you had more time/fee?

I would have formatted the heat map into Tableau software to allow a dynamic selection of a specific case highlighting the energy use pie diagram showing how cooling and heating loads can vary as a function of the orientation and aspect ratio.