Large Air Cleaner or Several Small Air Cleaners - Which is Better for a Large Open Space? Consumer seeks best home air cleaner solution

From: David Barnaby -
Subject: multiple air cleaners

Dear Deborah,
An air cleaner will work in multiple rooms only if they are fairly open. If a room has the door closed the only way to clean the air in that room would be for it to have its own air cleaner. However, if the door is open the air will circulate into the other room and eventually work its way into the air cleaner. A couple of factors that will affect how fast the air is cleaned would be how large the air cleaner is. The more CFM (cubic foot per minute) of air that is drawn into the air cleaner the more circulation you will have thus drawing the air from the adjoining room that much faster.

Also, as the particulates in the air space are reduced those remaining will equally space themselves apart through dispersion so over time they will work their way toward the opposite side of the air space. The air circulation of the air cleaner will create a vacuum effect so the particulates will be drawn into the air cleaner. This process makes it possible for the air on the opposite side of the room to be cleaned.
Furthermore, the cleaning process in a large area or multiple open rooms is enhanced if there is increased circulation through the use of fans. If you have a fan pulling the air out of an adjacent room it will be easier for this air to be drawn into the air cleaner to be cleaned.
As far as your question concerning the large open space and the use of one large air cleaner as opposed to several small air cleaners, the main ingredient is the air changes per hour. You need to take the cubic feet of the air space and divide that into the cubic feet of air that is cleaned by the unit in an hour. For example, if the air cleaner you are considering cleans 100 CFM then it will clean 6000 cubic feet an hour. If your room is 125 square feet with an 8 foot ceiling than it is 1000 cubic feet. Therefore, this air cleaner will do 6 air changes in an hour. Acceptable air changes per hour will range from as low as two on the IQAir HealthPro unit to around 6 on the Blueair unit. Two to four air exchanges is a good norm to use when measuring your room for the right size unit. In conclusion, several air cleaners positioned throughout your air space would be able to clean the air in the area faster than one large unit even though you still could clean the area with one large unit. This would be especially true if the overall area is subdivided into several small rooms with limited openings. This would reinforce what I said earlier about fans running in the various rooms to help circulate the air. The main thing to consider is that one large unit will take longer and you would need to run it longer and on its highest speed.
If you have any questions concerning any of this please feel free to call or respond.
Thank you,
Dave Barnaby
IQAir Healthpro air cleaners are found here:

Blueair air cleaners are found here: