 # Airflow

When looking to get a new air purifier, one of the most important parameters you should look for is airflow.

The airflow shows how much air can the purifier circulate in terms of volume (space) per time.

For example, the AirCleaner Personal has a maximum airflow of 285m3/h. That means that theoretically, in a room with dimensions 12m*12m*2m = 288m3 it will take around 1 hour for all the air in the room to circulate through the purifier.

So, why is this important to know? Because the bigger the room you want to clean, the higher airflow your purifier will need.

AirDeveloppa recommends you always look for the airflow parameter when buying a new air purifier, otherwise, is like buying a motorbike without knowing how many CCs the engine has!

We have seen some small, portable HEPA mini air purifiers in the market. Because of their dimensions and because they are only powered by 5V through USB, they can only have a small airflow, and the tiny filter must get dirty really quick. This means they can only be effective in very small spaces such as inside of a car.

This is an example of how you can end up buying the wrong product if you don’t know the right information.

### How we calculated Airflow

AirDeveloppa measured the airflow of the AirCleaner Personal the following way.

Using a wind speed meter, the wind speed was measured at 3 different points of the exhaust pipe at max speed.

Then, assuming point A covers 85% of the total area, point B covers 5% and point C covers 10%

Average Wind Speed = (9.2m/s*0.85)+(5.1m/s*0.05)+(6.5m/s*0.1) = 8.725m/s

Now that we have the average wind speed, the other parameter we need to calculate is the area of the exhaust pipe:

Area = (pi*(0.11m/2)^2)-(0.001m*0.11m*4) = 0.009m2

Finally, we can calculate the airflow in 1 hour:

AW = Average Wind Speed*Area*1h = 8.725m/s*0.009m2*3600sec = 282.69m3/h