Negative Ion

Our advice for those considering a negative ion air cleaner is “buyer beware.” These air cleaners are often marketed as having health benefits and mood enhancing capabilities, however, there is evidence to suggest that they may be doing more harm to your health than good.

Ions are particles in the air that have acquired a positive or negative electrical charge by losing or gaining an electron. High levels of positive ions are believed to cause depression and migraines, while high amounts of negative ions are regarded as having soothing and rejuvenation effects. Just before a lightning storm, the air is heavily charged with positive ions, and afterwards, it is highly charged with negative ions, leaving the air smelling fresh and clean. There are also large concentrations of negative ions around waterfalls, rivers and mountains, making the air highly refreshing.

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Negative ion air cleaners are designed to put more negative ions into the air by using high voltage needles or wires to add an extra electron to air molecules and then dispersing them back out into the room. These negatively charged ions then attach themselves to contaminants, which are generally positively charged. The negative charge is imparted to the contaminants, which then attract other positively charged particles, clumping together until the particles become heavy and fall to the floor. In addition, the negatively charged contaminants are attracted to positively charged surfaces like floors, walls, furniture, curtains and clothing, removing them from the air.

Aside from possible mood enhancing benefits, the advantages of negative ion air cleaners are that they are very quiet to operate because they don’t have a fan, and there are no expensive filters to replace. In addition, the air will smell fresher because of the negative ions.

However, there are also numerous disadvantages. While the air in the room may be cleaner, the room itself may actually be dirtier as contaminants are deposited on surfaces, requiring constant vacuuming of carpets and furniture. Moreover, the ionizer will deposit “soot” near the output vent, creating a “black wall effect” that requires regular cleaning.

In addition, since the contaminants are not actually removed from the room, movement may stir them up and cause them to be released back into the air. The lack of a fan is also problematic, as negative ions can lose their charge quickly. As a result, many air cleaners of this type are only able to project negative ions to a distance of 3 feet, providing limited coverage. In fact, Consumer Reports has stated that air ionizers without fans do not perform to high enough standards compared to conventional HEPA filters. However, even with forced air, many units can still only disperse negative ions to around 7 feet.

More importantly perhaps, negative ion air purifiers can produce ozone – a known lung irritant and asthma trigger. While many units produce negligible levels of ozone, there are some brands and models on the market that far exceed government safety standards. There is also some evidence to suggest that inhaled ionized particles may stick to the walls of your respiratory system and cause lung irritation and allergies. Although the air in a room may smell fresher, breathing it may actually be harmful to your health.

The bottom line is that if you don't mind vacuuming and cleaning, and are not concerned about ozone production, ionizing air cleaners may be a good choice for you because the unit itself requires no maintenance. However, Modern Alchemy Air Purifiers does not currently recommend or sell negative ion air purifiers because of the potentially adverse health effects.

For a safe alternative to negative ion air cleaners, see our HEPA and better-than-HEPA units from AllerAir, Blueair, Austin Air and IQAir

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