The '30-pyeong' label on a purifier is not your home's floor area — it is rated coverage derived from CADR. For the same 33㎡ living room, Korea's 130% rule asks for CADR 5.6 while US guidance asks for 10.1.
Robot vacuums split on four things: suction (Pa), navigation sensor, mopping style, and dock. Most homes are fine at 4,000Pa with LDS LiDAR; caked grime needs 2kg-plus rotating pressure.
Multiply the floor area of the room you dehumidify — 0.76L per pyeong (3.3㎡) for apartments, 1.02L for houses. A 20-pyeong living area needs a 15L class unit; laundry-drying in a closed room needs only 10L. Full sizing table inside.