Can a vacuum cleaner be used to purify the air in a small room? A hepa vacuum cleaner will pick up fine dust from the floor, filter it and send the clean air out through the exhaust.  However with movement in the room fine dust will also be goinng up in the air and so the vacuum will not take it in and this fine dust will settle hours later.
As far as i can see, a vacuum cleaner is very similar to an air scrubber, takes air in, filters it and sends it out. 
1) is it not possible to close windows and leave the vacuum on in the middle of the room and expect it to filter fine dust in the air/room?
2) what if i maneuvered around and tried to vacuum the air aswell as the floor for several hours, would this do the job?
3)is a air scrubber/filter necessary?
The room in question is about $18\,\mathrm{m}^2$ and the vacuum cleaner i intend to use is a sealed hepa unit which is about 500 air watts and says it can do $58\,\mathrm{L/s}$ which i think is litres per second.  Please give general answers to the questions I have asked aswell as specific to the vacuum and room in question.  Thanks.
 A: As a first approximation, assuming your room ha a ceiling of ~3-3.5m, the total volume of the room is anywhere from $54m^3$ to $63m^3$ and at that would mean the total volume of the room is up to 63,000 liters. So at 58 liters per second the room would have the whole volume of air changed in about 18 minutes. 
You can pretty well assume that the vacuum (mostly) gets all the air because as it sucks air the space in front of the intake is emptied and "new" air comes in. But then you'd have to know the air circulation around the vacuum. That is, the air near the ceiling may take longer to cycle down. 
Intuitively my sense is that a vacuum near the floor with the exhaust letting out near the ceiling (like, maybe you attach a pipe, like on a dryer) would get you the 18 minutes to recirculate all the air in the room through the vac, since the air in the vac is heated a bit. Otherwise you have to account for the air near the floor not fully mixing. Thinking about it I suppose a very tightly closed room with a fan would do the trick, to ensure full mixing (and recirculating) of air. 
Does this make sense to you? 
