What's wrong with ionizers? There are many problems associated with ionizers. To perform air cleaning, meaning removing larger particles of dust, you need a very large amount of ions. More than has been recognized as a safe level. According to air science, indoor air has 100 to 200 ions per cubic cm, outdoor fresh air has 200 to 500 ions per cubic cm, and a fresh clean forest will have 1,500 to 5,000 ions per cubic cm. Ion generators typically produce more than 1,000,000 to 10,000,000 per cubic cm. This is simply too much. This large amount of ions are needed to push the particles to the walls and floor. In fact for ionization to be truly effective, ionizers must generate so many ions that they can cause headaches and sore throats.
More ionization is not better. The fact is even with this overabundance of ionization there is only limited, temporary air cleaning being done and zero air purifying being accomplished. Nothing is being killed by the ions. Nothing is being purified.
In other words ionizers are simply pushing around the floating dirt to the surfaces in your room! The problem with this is that the same dust can be kicked right back into the air. The dirt that does not begin to float again will stick to whatever surface is close. After a few months walls, floors, appliances, and furniture begin to build up a layer of dirt on them. If you put an ionizer on a table near a wall, the wall will develop a black halo of dirt in just a couple of days. Some ionizers claim to have plates that collect the dirt. In truth they can only collect less than 5% of the dirt. The other 95% of the dust, bacteria, and mold spores end up on your walls, floors, and belongings.
How is an ion that is shot across a room, attaching itself to a dust particle, supposed to travel all the way back to a dust collection plate on an ionizer from 10-20 feet away? The answer is it cannot be done. In fact if the ion does travel across the room, the particle it attaches itself to will adhere to the closest possible positively charged surface, that being your walls, floor, ceiling or anything else it is close to. This is not rocket science, it is simple physics. Even ionizers that draw air through them and collect dust as it is passing by are not efficient for capturing dust. They are still emitting ions far into the air in front of the machine.
These ions then attach themselves to dust particles. If the ion flow or the airflow of the ionizer is strong the dust will never be able to find it's way back to the ionizers collection plate. The dust will then, of course, attach itself to ANY positively charged surface in your home. If the ionizer is weak it will do hardly any good at all at capturing dust particles. If it has a strong ionic or airflow then the ions will break away from the machine and cause the dust to be collected on the surfaces of your home.
Either way an ionizer will not eliminate dust. Many ionizer ad's claim that the ions will eliminate dust. What does that mean? Where does the dust go? It HAS to go somewhere! This nonsense that ions will simply "drop the dust out of the air" to be vacuumed up at a later date is simply not true. Simple physics state that the dust MUST adhere to the closest positively charged surface, most likely your walls and furniture. ALL ionizers will cause the dreaded "black wall effect" where they will turn your walls black with dust.
Six months after you start using an ionizer you will have MORE bacteria collected in your home than before you started! The use of ionization only makes a dust problem WORSE! Realize that all so called "air cleaning" ionizers do is limited to pushing around lightweight particles of dust. They cannot effectively kill odors, nor can they remove large particles such as pet dander.
For removing larger particles of dust and dander a HEPA filter is much more effective than an ionizer. HEPA filters collect the dust and dander rather than just pushing around the room as an ionizer does, so that it does not start floating around again. The idea is to remove the dust from your home, not simply move it from here to there. You should look for a hospital grade HEPA filters If dust and odors are present, a combination of a HEPA filter and a Carbon filter is the best method of dealing with the problem.