How ionizers work

How an Ionizer Works

Negative ions can be be produced by copying any of the ways that nature uses - ultra violet (lamps), radioactive sources etc. Indeed a bathroom shower provides a plentiful supply! But it most cases it is either too dangerous, too expensive or just impractical. For this reason most manufacturers use the method called "corona discharge" which is similar to lightning.A high voltage (but at extremely limited current, for safety) is applied to one or more needles. Electricity is a flow of individual electrons. And these electrons, supplied by the internal circuit, are pushed down the needle towards the point. The nearer they get to the point, the closer they become forced together. Electrons naturally repell each other, so as they reach the tip, the pressure becomes too much and they "jump" off, onto the nearest air molecule, turning it into an ion.By adjusting the voltage level, the needle profile and the various materials used, this process can be made very efficient.Negative ions again repell each other, so they are driven from the needles as a gentle breeze, forming a dense "cloud" in front of the ionizer, which disperses in all directions into the room.

Air ions have two qualities:

  • They are beneficial to health by their inhalation and absorbtion.
  • They are very efficient air cleaners, particularly of the smaller sized, more hazardous particles.

The ions leaving the ionizer are small, high velocity ones. These are found to be most beneficial to health. If they collide with particles of smoke or pollution near the ionizer, they pass on their "static" charge. This particle is then strongly attracted to the nearest "earthed" surface. (which could be a wall or the shelf on which the ionizer is placed - so make sure it is washable!) Out into the room the ions naturally begin to slow down. As they drift, pollutants such as dust, pollen, cigarette smoke and even vapourised substances like aerosol propellants and car fumes are attracted to and cluster around the ions. This has the effect of making the ion grow in size. There comes a point where it is too heavy to be carried in the air, so it falls to the ground.The ability of an ionizer to remove very fine particles from the air makes it extremely valuable for health. Recent studies indicate that the smaller the particle, the harder it is for our immune systems to cope with. So ionizers have a "double action" effect. They excel at removing microscopic particles - the most harmful - and at the same time they restore a "vitality" to the air - which our bodies appear to need for their everyday functioning. The quoted range of an ionizer is usually the distance at which it can maintain a certain concentration of ions. (the standard figure is 1000 ions per cc of air - said to be the lower threshold level for health purposes). However most ionizers will have a cleaning effect over a greater distance. A very important point to be aware of: A badly designed ionizer may produce ozone, and with it nitrous oxide. These are toxic substances and can cause respiratory difficulties and stinging eyes (often the very thing they were purchased to cure). The WHO (World Health Authority) guidelines, say that the maximum acceptable level of ozone is 0.1ppm (parts per million). So when purchasing, make sure it is from a reputable company. (We have tested some cheap models in the past, and they really are unpleasant to use).