See how buoyancy, temperature difference, and building height combine to drive airflow through a structure — and where the neutral pressure level lands when openings change.
BUILDING PHYSICS TOOL
Warm air is less dense than cool air, so a difference in temperature between indoors and outdoors sets up a pressure difference across the whole height of a building. Adjust the conditions below and watch the cross-section, neutral pressure level, and pressure profile respond in real time.
Warm air is less dense and lighter, so it rises; cooler, denser air sinks and displaces it.
Rising warm air creates positive pressure high in the building and a vacuum effect low in the building.
Every building has a plane where interior and exterior pressure are equal, dividing the two zones.
A longer vertical air column increases the overall pressure differential, so taller buildings feel it more.
Dots represent air moving through the interior; arrows show flow direction and relative strength at each opening.
