Fascinated with the ventilation systems in CIRS Building, we took our aim to study and share the ventilation flow of the building. The flow of ventilation was observable through launching a paper propeller from upper levels. When the paper propeller descends, we saw that the propeller sways side to side. The propeller would descend at a constant position at certain height, and this was concluded to be because of interference on the floor with the flow. Our installation was having participants launch the propellers down, and have them observe the flow of ventilation flow. The landing spot of the propeller was marked with pieces of paper, and this was to observe the trend of the landing spot.