Premnath Sundharam from the Visualize Green blog contacted me to draw attention to a Sankey diagram template he has made and that is available for download on his site.

The diagram is for predicted energy intensity for buildings. An Excel template is provided that allows entering the data. You can use this with the free trial version of e!Sankey (registering required). All elements of the diagram and the entry sheet is explained in detail by Premnath. In regard to the unit (KBtu per square foot per year) he says:

Last but not least, kBtu/sf/yr is becoming the universal (US) unit of communicating building energy consumption. This unit is called the EUI – Energy Use Intensity and since it is a simulation of how your building will perform, it is called PEUI – Predicted Energy Use Intenisty.

Good stuff, Premnath! Thanks for making this available to everyone.

Note November 2011: Also look at Premnath’s Energy Story here.

This website on energy optimized building features a case study of a students dorm building at Wuppertal, Germany. [On a side note: it is quite striking that when I browse for new Sankey diagrams on the web, I come across them on German websites. Herr Sankey could well have been a German…]

The two Sankey diagrams shown along with the article visualize the heat energy flows before and after the optimization measures taken.

before:

after:

Flows are in kWh per square metre per year. The first diagram breaks down heat consumption into heat used for room heating and for warm water preparation. In the second a new heating system has been installed providing heat mostly over the air circulation system. Only some static radiators remain. [Thanks Thomas for helping me with the translation/explanation].

Apart from the use of a fancy color, the Sankey diagrams are well done and comprehensible. Flows are to scale.