The filling box is a mechanical engineering technique used to visualise buoyancy-induced airflow. An acrylic model is submerged into a tank of fresh water and then filled (or injected with) dyed saltwater. Fresh water simulates less dense (warm) air and dyed salt water represents dense (cold) air. In the mirrored image, dyed salt water represents warm air and fresh water cold. This technique enables visualisation of displacement and stack effect ventilation as well as any flow based on thermal differentiation.
Photographs of the filling box models illustrate building scientific principles of buoyancy, but they are also visceral reminders that buildings are in constant collusion with their atmospheric surroundings. The models leak,and they leak somewhere, and that somewhere leaks beyond, inaugurating a series of cascading environmental effects. They are reminders of Evangelista Torricelli’s observation in 1644 (when describing his discovery of thesensitive air-weighinginstrument, the barometer) that “we live submerged at the bottom of an ocean of the element air.”
Fabrication documentation is available in my book.