Naturally occurring in nature, the negative ions are small particles in the air we breathe. These particles, mostly oxygen ions (O²), are very present in unpolluted places such as the mountains or the sea. They can also be produced by an air ioniser. Urban and polluted environments will rather concentrate positive ions (0²+).
These electrically charged particles have a direct impact on our well-being. Do you remember the last storm that broke out? Before it started, the air was heavy, heavy... This is because the air was saturated withpositive ions.
. When the storm was over, the electrical charge in the air was reversed and the air was charged with negative ions, giving you a feeling of relief and well-being. A thunderstorm is a natural phenomenon, but technology can replicate this phenomenon: it is possible to create negative ions while neutralising positive ions.
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What is ionisation?
Ionisation consists of changing the charge (positive or negative) of an atom or molecule. The term ion therefore refers to atoms or molecules that have gained or lost several electrons in relation to their number of protons. Positive ions are also called : cations and negative ions : anions.
Positive ions can be produced by an appliance (television, electric heating, air conditioning, etc.), pollution or before storms. They cause a feeling of nervousness and tension. Negative ions, on the other hand, give a feeling of calm. They are particularly suitable for people who suffer from headaches, respiratory diseases and depression.
Where can negative ions be found?
Negative ions are naturally concentrated in humid places such as the sea, near a river or after a storm: the colliding of water molecules creates negative ions in the air. The feeling they bring is generally that of "being in a good mood". well-being ". However, they are found almost everywhere, but in different concentrations in the air, as shown in this table:
| Location | Negative ion concentration/cm3 |
|---|---|
| At the foot of a waterfall | 10 000 à 50 000 |
| In the mountains (around 1200 metres) | 8000 |
| By the sea | 4 000 |
| In the forest | 3 000 |
| After a storm | 2 000 à 5 000 |
| In the countryside | 1 000 à 1 500 |
| In urban areas | 20 à 500 |
| In flats and offices | 10 à 50 |
| In air-conditioned premises | 0 à 10 |
The ideal living environment is air with 1,500 to 2,000 negative ions/cm³. The best way to achieve this healthier air in a room, balanced with negative ions, is with an air purifier ioniser. A good quality ioniser should be able to produce 3,000 to 5,000 negative ions/cm³ in a 2 metre radius.
How to purify the air with an ioniser?
What you need to know All airborne particles are neutral or positively charged.
Air purification by ionisation consists of injecting into the air a flow of negative ions produced by an ioniser purifier type device. The released electrons are captured by molecules in the air, mainly oxygen molecules, to form negative ions. These negative ions combine and negatively charge the electrically neutral particles suspended in the indoor air (pollution, viruses, odours, bacteria, etc.). The initially positive particles are then neutralised and in turn acquire a negative charge.
Negative particles repel each other and end up being deposited by electrostatic attraction on surfaces that are positively charged (floor, walls, furniture, fabrics....). Oppositely charged particles will attract each other and form heavier particles that will deposit on surfaces more quickly.
The ionisation function can be very effective in improving the air quality in your home and your health, if combined with a floor vacuum cleaner: this prevents ultra-fine particles such as dust from being blown back into the air in your home. We recommend its use in our selection of air purifiers to combat allergies.
Where to place your air purifier?
An air purifier ioniser will be effective if it is placed high up on a flat surface. It is also advisable to place it in a place where the air can circulate around the device. As its action is limited to the room where you are located, it is best to place it in your bedroom or a living room so that it can effectively purify the pollutants in the ambient air.
Ideally, you will have purchased an air purifier with a HEPA filter. In addition to neutralising dust particles in the air, your appliance will be able (with the help of its filter) to capture volatile organic compounds and pollution present in the indoor air (pollen, dander, animal hair, fine particles, bacteria and viruses, etc.).
The efficiency of the filtration will of course depend on the quality of the filter used. So, depending on the products you are considering, try to choose an ioniser purifier with a HEPA filter combined with an activated carbon filter.
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Discover our selectionChoosing an ozone-free air ioniser
Ozone is an essential gas for life, but it is important to know that it is harmful to our health if we breathe it (even in small quantities). It irritates the respiratory system and the eyes. It also causes coughing and shortness of breath. Ozone pollution is often compared to smog.
Some models of ionizing purifiers will tend to emit ozone. To avoid this problem, be sure to : do not buy an ioniser that uses oxidising (or destructive) techniques such as ozonation or plasma. When used, both air purification systems generate ozone which is harmful to your lungs and health.
Ionisation and standards
After research, we could not identify any regulation specific to the use or marketing of indoor air cleaning systems in France. To date (19/11/2021) and unless we are mistaken, only the State of California (USA) regulates ozone emissions from air pollution control devices, which must not emit more than 0.05 ppm of ozone.
However, there are three French standards for air purification and filtration devices used by purifiers:
- The NF B44-200 standard (also applicable to air conditioners): it allows the intrinsic performance of stand-alone scrubbers to be assessed.
- Standard NF EN 16846-1 Photocatalysts: measures the effectiveness of photocatalytic devices for the active removal of VOCs and odours from indoor air in confined spaces.
- The experimental standard XP CEN/TS 16980-1 This section deals with continuous flow test methods and the determination of nitric oxide (NO) degradation in air by photocatalytic materials.