What is behind the different filter classifications? A lot of information, many standards, and little clarity. Let us explain.
In the air purifier market, apples are often compared with oranges. The variety of filters on offer and their advertised cleaning performance is almost as large as the number of manufacturers themselves. So, how can we find a way through this jungle of offers?
It's important to understand a few things:
What exactly does HEPA mean?
Is HEPA in everything that says HEPA on it?
Worldwide there are several different filter classification standards. The main goal of these standards is to create a scale with which different filters can be compared. The focus is on several aspects. Let's have a look at the main three and how they are measured:
Filterable range (particle sizes)
Knowing what is behind the different classifications and values allows you to better choose the right product for your needs.
So here is an explanation with 2 examples of what is most important about air purifiers and what you can look for when buying a product:
The various filter classification standards each focus on one of two main factors:
Most important for an air purifier is always a combination of these two values:
Very high filter efficiency is only helpful if a high enough volume of air per hour can also be filtered with this efficiency.
The product of example 2 thus brings an overall better cleaning performance for the room size, despite the lower efficiency than the device of example 1.
Filters with very high-efficiency values are of course important for labs, hospitals, and similar facilities as there the room air can not be filtered multiple times to be cleaned but should be cleaned as much as possible in one cycle before entering the room through a ventilation system. With a special focus on microbes, viruses etc.
But for a mobile home use device that is mainly used for filtering dust, pollen, pet dander and smog it's much more important to have a device that can achieve a CADR suitable for the room size you want to use it in, while the filter can be of lower efficiency.