An air ionizer (or negative ion generator or Chizhevsky lamp) is a device that uses high voltage to ionize (electrically charge) air molecules. Negative ions, or anions, are particles with one or more additional electrons that confer a net negative charge to the particle. Cations are positive ions that are missing one or more electrons, resulting in a net positive charge. Some commercial air purifiers are designed to generate negative ions.
Another type of air ionizer is the electrostatic discharge ionizer (ESD) (balanced ion generator) which is used to neutralize static charge. Ion generators work by charging the particles in a room so that they are attracted to walls, floors, tables, curtains, occupants, etc. Abrasion can cause these particles to be resuspended in the air. In some cases, these devices contain a collector to attract charged particles back to the unit. While ion generators can remove small particles (for example, some have suggested that these devices provide an advantage in correcting an alleged ion imbalance), no controlled study has confirmed this effect.
The CADR measures the amount of filtered air that circulates over a short period of time and was originally designed to classify air filters for multimedia use. When deciding if an air ionizer is right for you, it's important to weigh the pros and cons. The California Air Resources Board has a page listing air purifiers (many of them with ionizers) that meet its indoor ozone limit of 0.050 parts per million. The California Air Resources Board provides a list of air purifying devices that emit hazardous amounts of ozone. The ionizer with a fan base uses its fan to circulate air quickly around the room, but it is noisier and consumes more energy, while those of the fanless models distribute the air slowly, so they take longer to purify it, but are quieter and more energy efficient. Decades later, British electrical engineer Cecil Alfred “Coppy” Laws developed the first air ionizer for domestic use. In response to the COVID-19 pandemic, people have been installing ionizers in offices and restaurants.
Ionization decreases dramatically with distance (even in ducts), so air ionization is rarely used for this purpose and only for elements immediately adjacent to the ionizer itself. Unlike air purifiers and disinfectants, which use fans and filters (HEPA or carbon) to trap harmful contaminants inside the device, an ionizer “removes the impurities that float around the room, attacking the molecules and neutralizing them”. Ionizers use electrostatically charged plates to produce air ions with a positive or negative charge (for example, N2+ or O2−; these primary ions immediately group together with other air molecules, such as H2O) to which particulate matter adheres. Installing an air ionizer can be beneficial for many reasons. It can help reduce airborne allergens like dust mites and pet dander as well as reduce odors from cooking or smoking.
It can also help reduce static electricity in your home or office. Additionally, it can help reduce airborne bacteria and viruses like COVID-19 by neutralizing them. When considering an air ionizer, it's important to consider both its advantages and disadvantages. On one hand, it can help reduce airborne allergens and odors as well as reduce static electricity in your home or office. On the other hand, it may not be as effective at removing larger particles like pollen or smoke particles from your home or office environment. It's also important to consider how much energy an air ionizer will consume when deciding if it's right for you.
The fan-based models will consume more energy than fanless models but will circulate air more quickly around your home or office environment. Additionally, some models may produce hazardous amounts of ozone which can be harmful if inhaled. Overall, installing an air ionizer can be beneficial for many reasons but it's important to weigh both its pros and cons before making a decision. Consider how much energy it will consume as well as any potential health risks associated with ozone production before making your decision.
