How to choose an air purifier?

11/23/2020


Indoor pollution is an established fact, it is no longer a subject of debate, it exists because of everyday life (dust, viruses, hair), the emanations from furniture and other furnishing objects (chemical pollutants) and the contribution of outdoor pollution.

The air purifier can be a solution to improve the air quality of a room.

The effectiveness of home air purifiers is often questioned. In fact, certain precautions should be taken: an air purifier that does not work properly can emit harmful molecules. All air purifiers do not work in the same way and are not designed for the same type of surface.

We advise you to leave aside the material "general public" and to turn to less known brands but which manufacture professional material.
The price difference between the "top of the range" consumer equipment and this type of equipment is finally small and their actual performance has nothing in common.

On this subject you can read the following article: What are the real performances of indoor air purifiers for the general public?
What is the most efficient air purification system?

The most efficient systems are filter purifiers. They should have at least three different filtration systems:

  •     A pre-filter (often made of foam) that captures dust, pollen, hair, etc..,
  •     An activated carbon filter that removes volatile organic compounds known as VOCs and odours.
  •     A HEPA filter, i.e. High Efficiency Particulate Air, which retains fine particles in suspension. This technology is very basic and all its effectiveness lies in the quality of the filters.

Attention there are several levels of HEPA filters which have different levels of efficiency.
HEPA Class Retention (global) Retention (local)
E10 > 85% -
E11 > 95% -
E12 > 99.5% -
H13 > 99.95% > 99.75%
H14 > 99.995% > 99.975%
U15 > 99.9995% > 99.9975%
U16 > 99.99995% > 99.99975%
U17 > 99.999995% > 99.9999%

What are the other air purification systems?

There are also devices whose performance is difficult to verify:

    Ionizers purifiers which diffuse ions in the air which allows to act directly against the particles which fall on the ground or are absorbed by the purifier.
    The cold catalytic filter which is supposed to neutralize formaldehyde.
    Photocatalysis, light, or UV radiation, activates a catalyst (often titanium dioxide), which causes chemical reactions that degrade organic molecules.
    Ozonation (used rather in a professional environment).

The choice of a device with a filter remains a safe and durable solution provided that some maintenance is carried out and the filters are changed regularly. It is therefore necessary to check how easy it is to buy and then change the filters and at what price (The carbon filter is changed approximately every 6 to 12 months, the HEPA filter every 12 to 24 months).
What parameters should I look at before getting equipped?

You also need a purifier adapted to your surface area (m²) with sufficient airflow (expressed in m³/h). As an indication, we recommend, according to our experience the following :

Surface 300 Sq/Ft   450 Sq/Ft 650 Sq/Ft 1000 Sq/Ft 1500 Sq/Ft
Air flow rate 1100 Ga/Mi 1450 Ga/Mi 2200 Ga/Mi 3000 Ga/Mi 5000 Ga/Mi


Many options can be included depending on the brand and model of purifier :

  •     An indicator light for filter maintenance
  •     Air quality display
  •     A silent mode
  •     A connected grip
  •     An automatic mode, a timer, a scheduler...

How do you know if your air purifier is effective?

Ideally, before the installation of an air purifier it is easy to make an inventory of fixtures by a precise measurement of VOC and aldehydes (by passive sensor analyzed in laboratory) and possibly a measurement of fine particles by a sensor.

And after installation, to check the validity of the installation of a system by a control measurement after a few weeks of use.

Indeed the performances of these purification devices can only be certified by an external control, their integrated electronic sensors only giving global information (total VOCs for example).

 


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