Contaminant Distribution in Air-con Room

Jules

I am doing a study on the distribution of dust particles in an air-conditioned room.

To simplify the model, the room consists of one exhaust, two vents for return of air from the room to the air-con system, and 4 vents for the air from air-con and the environment back into the room.

I was given the values of the flow rate of air thru the exhaust (entirely and directly out into the environment), the 2 vents where air is recirculated back into the air-con system, and the flow rate of circulated air+fresh air into the 4 vents into the room

My question is how I can get the value of contaminant concentration at various time interval at the two vents which the contaminated air goes into the air-con system. I need the value so that assuming the efficiency of filter in air-con is 80%, perhaps I can indicate that the incoming air is being contaminated with 20% of contaminants that escapes into the air-con system.

I think that is the only way to model spread and removal of contaminants with time in an air-conditioned room. Can anyone help me on this?