Every speck in this room is simulated. They drift on a real airflow field made by the
windows you open, the fans you run, and the hot air coming off the hob. The PM2.5 number
is counted off the particles — it is not a score someone handed you.
1
Air changes per hour is the number. A purifier's CADR divided by the room volume gives the ACH it could deliver. This room is 48 m³, so a 260 m³/h unit tops out at 5.4 ACH.
2
That ceiling is not a promise. The air has to actually reach the intake. Shove the unit into a corner behind the sofa and the delivered ACH falls off a cliff. Watch the two numbers separate.
3
Sources beat filters. A hood ducted outside removes cooking smoke before it is ever room air. No purifier can match capture at the source.
4
Ventilation is not always the answer. If the air outside is dirtier than the air inside, opening a window makes the room worse. Round three will show you.
DRAG orbit the room ARROWS move the floor cursor ENTER place 1–4 pick a unit [ ] fan speed Q E windows H hood V HVAC L seal F filter B the source SPACE fast forward R restart