The idea of an Indoor air purifier is that it circulates the indoor air through the machine thus removing pollutants, particles, VOCs, Bacteria, viruses etc. thus returning clean air to the room. This is not only essential for dealing short term pandemics, but also to maintain healthy spaces for the long term.

Filtration efficiency
It is very important to know how much of the pollutants the purifier can remove when the air passes through the machine. This is called filtration efficiency. It can get close to 100%, which is often something that the air purification companies like to promote as it is relatively easy to reach this level. But what really matters is the actual air flowing through the purifier, which is something that is not always talked about. For us to have clean air, filtration efficiency alone does not tell us enough.  Only the air circulated through the purifier is filtrated. If only a portion of the room’s air goes through the purifier, the rest stays polluted, no matter how high the filtration efficiency is.

Clean Air Delivery Rate (CADR)
Generally, the whole air volume of a room should be fully circulated through the air purifier at two to five times per hour. The amount of air flow through the machine is as important as the filtration efficiency of the purifier. Because of this the best criteria for selecting a proper air purifier is the Clean Air Delivery Rate (CADR), the amount of clean air delivered per hour (m3/h), which is calculated by multiplying the purifier’s filtration efficiency with the air flow through the purifier.

Particle size
When it comes to air pollutants, the ultrafine particles are the most harmful as they are most easily absorbed into the lungs. They are also the most difficult to observe with sensors and the hardest ones to catch with filters without compromising on the air flow.
When comparing different CADR values, the filtration efficiency should be measured for the same particle size, preferably for smaller particles
like PM1 or even smaller, not only for PM2.5. Before buying an Air, Purification check your CADR rates are shown and what particles are being measured in that CADR rate.

Please feel free to contact us for a free consultation on Air Quality and options to deliver clean air to your commercial space.