Air Conditioning dust

[Jollygoodfellow]

12 hours ago, GeoffH said:

If it's 'thick black' dust then it's likely diesel exhaust particulates which can be carcinogenic (mainly the finer stuff though not the thick stuff like you're describing).

There are a lot of diesel vehicles in the Philippines and exhaust gas emmisions from jeepneys can be quite bad.

 When I say thick I mean a decent covering.

Thing is jeepneys have not operated in over a month and hardly any traffic at all.

[Jollygoodfellow]

9 hours ago, Heeb said:

If the window unit is sealed properly then the dust is coming from inside, it will suck in air from other rooms especially if the door is shut since it will create a vacuum and pour in from the adjoining space under the door

It's a cond unit and not many rooms. The buildings hallways are cleaned every day and I doubt if enough inward draft would pull dust out of other empty units?

 

8 hours ago, Dave Hounddriver said:

However all the old window units I bought in the Philippines had a mechanical 'fresh air/recirculation" lever that opened or closed a half inch diameter hole to the outside.

The user could allow some fresh air in using that lever.  Not sure if it made much difference but I can see how outside air would get in that way. 

None of these including my own have a leaver but I do know the ones you are talking about but dont think they have been made like that for years?