The effective working area is the room size that the purifier can effectively clean and it is intrinsically related to the Airflow, filter efficiency and the room size.

This is the single most important parameter you must look for when looking for an air purifier, as you should buy one that will work well for your room size.

To calculate the effective working area, you need to know the airflow and filter efficiency of the air purifier. If you don’t see these parameters on the specifications table of the product you are intending to buy, the manufacturer or vendor could have just created the effective working area from a random assumption instead of real data.

### How we calculated the Effective Working Area of the AirCleaner Personal

From our tests, and ESRC Validation Report, we know the following parameters:

Filter Efficiency = 99.86%
Airflow = 285m3/h or 167.64 cfm

We can now calculate the Clean Air Delivery Rate (CADR) of the AirCleaner Personal:

Now, according to the Association of Home Appliance Manufacturers, for a room with an 8ft (2.44m) ceiling, the CADR is multiplied by 1.55 to find out the effective working area:

Effective Working Area = 167.4*1.55 = 259.47 sqft = 24.1m2

Working backwards, if you know your room size, you can convert that value to sqft and then divide it by 1.55 to get the necessary CADR.

Room volume = 25m2 = 269sqft