Indoor Air Pollution (II)

The significance of electrical charge

In my previous post after talking about an effective way to get rid of dust mites I mentioned air purifiers as one of the main solutions. Yet how do they work? I don’t want to delve too deeply into the science of it but it is effectively based on a few naturally occurrences. That is a thunderstorm and the ozone in the stratosphere many miles above our heads.

The Thunder Storm concept

Have you ever been out in a thunder storm? Have you ever noticed how great you feel when you’re watching the cloud roll in from the distance? That is due to the negative ions. The science behind negative ions and their effect on human behaviour is still very much unknown and speculative yet studies have seen how they have a positive effect on how a person feels, whereas positive ions have the adverse effect. One story mentions a scientist who worked beside an electrostatic generator. On days where it was throwing out positive ions he would end work in a foul mood, feeling fatigued and emotionally drained, yet on days it was producing negative ions he finished an eight hour shift bubbly and in good spirit. It has yet to be confirmed how, or why, these ions have this effect on the human body but it is proven that it makes a difference.

As for the use of negative ions in air purifiers, it works a little differently. The purifier charges air or gas particles negatively. These negatively charged particles then attach themselves to dust or any other airborne contaminants and are then attracted to a positively charged plate, removing the contaminants from the air. This could effectively be done the other way round, with positively charge particles being attracted to a negatively charge plate, yet it is because of the positive effects that negative ions have on the human body that the former technique is used.

A by product of a streak of lightning in a thunderstorm or in this purification method is…

Ozone (O₃)

You have probably heard of the ozone layer, which is up in the stratosphere where you will find the highest concentrations of ozone. Up in the stratosphere ozone’s main job is to filter out UV rays which are very damaging for your health. Used in an air purification process it does a slightly different job.

The ozone created by an air purifier is there to oxidize any nasty chemicals or contaminate in the air, effectively getting rid of them and any negative effect they may have on your health. You see the negative ions are useful for getting rid of the particulates (tiny particles of solid matter, i.e. dust or soot) as well as making you feel better by changing your mood yet the odours and all the harmful gases like carbon monoxide, nitrogen dioxide, carbonic acid, sulphuric acid and sulphur dioxide that may linger in you indoor air cannot be gotten rid of this way. That is why ozone is used as it can get rid of odours and any harmful substances that may be contaminating your indoor air.

All good air purifiers produce negative ions which in turn creates ozone. Couple this with good air circulation and your indoor air will be as clean as it is in the fresh wide open countryside, if not cleaner.