December 3rd, 2020 | Posted in General
Ionizer air purifiers are commonly used to clean the air and remove allergens and dust. However, unlike HEPA air purifiers, air ionizers don’t use fibers to trap pollutants, and they generally don’t use filters. So how do they work?
Here, we explain the process of ionization and how it applies to cleaner air, as well as what to look for when buying an ionizer air cleaner.
Ionization is the process of charging a particle with a positive or negative charge. This is accomplished by energizing a conductive fine wire, needle point, sharp point, or a sharp edge with high voltage DC. This voltage is positively or negatively charged, and creates an ionization field.
In addition to ionizer air purifiers and ionizer air cleaners, ionization is used in several applications, including laser printers, powder coat paint guns and disinfectant sprayers. The reason for charging the particles is so they are attracted to, and stick to, a surface, which can help with creating an even layer. This works well with the aforementioned applications because with printing, painting, or disinfecting, you get better outcomes when there are nice even layers.
Ionizer air cleaners work in one of two ways. The first method is when dust particles and allergens in the air are energized so that they are attracted to almost all surfaces, thereby knocking them out of the air. The other method is with bipolar ionization, where some of the particles in the air are positively charged and others are negatively charged. The benefit of the latter is that instead of being attracted to most of the surfaces in a room, the particles are attracted to each other. When the particles bond together, it forms a heavier particle that will fall out of the air quicker.
Some ionizers, known as electrostatic air cleaners, include an electrostatic collection plate, which uses both bipolar ionization to charge and bond the particles, and a collection plate to attract the heavy particles and trap them on its surface.
There are things to keep in mind when researching and buying ionizer air purifiers. First, you want to ensure that the ionizer is generating an ionization field, and not a corona discharge. Typically, with a corona discharge you will hear a hissing noise and see a faint bluish-purple light emitting from the sharp point. The reason you don’t want a corona discharge is it will generate high levels of ozone, which can be unsafe for people in the room. It is worth noting that ozone itself is highly reactive and likes to react with organic materials, which makes it good for disinfecting in unoccupied spaces.
When shopping for an ionizer air cleaner remember that units that do not produce a corona discharge were never really intended to be used to sterilize the particles or air moving through the ionization section. The air may end up being cleaner with these units, but it will not be fully sterilized.
As you search for the right air purifier for your environment, there are reasons to look towards other types of units. Typically ionizer air purifiers will only cover a small area. This means that if you have a large room or interconnected rooms, the unit may not be effective for the entire area. Also, if you actually want a room that is clean, including the surfaces, you will need a collection plate, or something for the particles to attach to. If not, the particles that are charged will just attach to the closest surface possible, or drop to the floor. The air may end up being cleaner with just an air ionizer without a collection plate, but the room won’t necessarily be cleaner.
To learn more about ionizer air filtration, check out How Electrostatic Filtration Works or see our guide on Troubleshooting an Electrostatic Cell.
At Air Quality Engineering, we carry a wide selection of electrostatic air cleaners for your air filtration needs. For assistance, contact us online or call 1-888-883-3273.