The air purifying world comes with many confusions and questions, one of them being the difference between electrostatic vs ionic air purifiers. These are two of the less known types of air purifiers that many people usually mix up or confuse with each other. So in this post, I will go through both of these air purifier types, list all of the differences, similarities, and effectiveness of each. So, which one is better for air cleaning, and what even is the difference between an electrostatic vs ionic air purifier?
In short, both electrostatic and ionic air purifiers use similar technology to reduce indoor air pollution. The biggest difference is how they utilize this technology. Both use electrical charges to clean the air. Electrostatic air purifiers achieve this through a series of plates, for both positive and negative electrical charges, located inside of the device. In contrast, standard air purifiers release only negatively charged particles. The air cleaning process for electrostatic air purifiers happens inside of the device, while for air ionizers it happens outside of the device. Overall, electrostatic air purifier’s performance is quite worse than air purifiers.
We have one common technology and the same principle, but two very different executions. Despite their similarities, these two air purifiers work quite differently. Consequently, they achieve different results in terms of air cleaning effectiveness. Let us take a deeper look.
Electrostatic vs ionic air purifier – how do they work?
Electrostatic air purifiers use static electricity to charge particles, both positive and negative, to purify the air. They do this through a series of special plates, which you can think of as filters. They have two sets of plates (“filters”) – one positively charged, and one negatively charged. As you already know from physics, opposites attract. So negatively charged particles from the first set of plates are therefore attracted and move towards the second set of plates with positively charged electrical particles. Here is a short video presentation of the process, so you can get a better idea.
Most commercial electrostatic air purifiers use only two sets of plates, which is not that great. Really good electrostatic purifiers use multiple plates, as shown in the video. These are usually big devices, as the whole point is to intake as much air as possible in order to effectively clean it.
The whole filtration process of electrostatic air purifiers happens inside of the device. So essentially polluted air passes through the device and gets intercepted by the negatively charged particles that are traveling towards the positively charged plates. Once intercepted, these air pollutants get deposited onto different filter layers, which hold them in place and prevent them from moving forward. As a result, only clean air exits the device.
In contrast, ionic air purifiers (also called air ionizers) use high amounts of voltage to produce and release only negative ions into the air. We measure the production of negative ions in cm3/second. Similarly to electrostatic air purifiers, these negative ions are attracted to positive or neutral particles – air pollutants fall into this group. Once a negative ion comes into contact with a positive particle/ion, it attaches itself to it. When this happens, the “newly” formed mass becomes heavy enough for gravity to pull on the ground. So once it hits the ground, it stays there and is unable to become airborne again. Here is a picture presentation of this process in a nutshell.
source: ionex-ionizers.com
The whole air cleaning process for ionic air purifiers happens outside of the device. This means that once all of the harmful particles have been neutralized, they have to be swept off the ground with a broom or a piece of cloth. There are some differences between air ionizers (like ionization element, how they produce negative ions), but they work the same way. In case you are curious and want to learn more about how air ionizers work, I have made a separate post which can be found here.
Air ionizers (ionic air purifiers) are mostly very small and portable, as they contain no filters and do not clean the air by intaking it. This is why they are considered one of the best cost-efficient types of air purifiers on the market.
Comparison chart
Here a short summary of electrostatic vs ionic air purifier operating differences.
Electrostatic air purifier | Ionic air purifier (air ionizer) |
Medium to large size | Small in size |
Pros and cons of electrostatic and ionic air purifiers
Both of these air purifier types come with their own set of advantages and disadvantages. Since their technology works on the same basic principle of polarity, some of the benefits and dangers will be the same.
Electrostatic air purifiers
They come with some pretty good advantages. I want to first talk about the set of plates or filters that store positively and negatively charged particles. These filters are a permanent type, which means that you never have to replace them. In other words, you can save quite a bit of money since one filter will last you a lifetime. Adding to that, the power consumption of electrostatic air purifiers is usually very low, making them a very budget-friendly option for air cleaning. Their noise production also is also generally low, making it a viable solution for the bedroom or a study room.
Sadly, there are quite a few drawbacks fo using Electrostatic air purifiers. Firstly, they have the worse air cleaning performance, measured by the MERV filter rating scale. While some models are much better than others, they still fall short in the air cleaning performance category. What makes the whole situation even more unfortunate is that they perform worse the more you use them. This is because of the permanent filters/plates which quickly become dirty, allowing more air pollutants to pass these filters. You need to regularly clean them, and that can lead to many other issues if you have to open the device – you can easily ruin it. Most electrostatic air purifiers also make ozone as a byproduct, which is very harmful to humans, pets, and plants.
Let us move on to air ionizers (or ionic air purifiers) and repeat this analysis.
Ionic air purifiers
Air ionizers have many of the same advantages that electrostatic ionic purifiers have. They are quiet, have very low power consumption (usually under 10 watts!), and no filters to replace, making them a very cost-effective method of air purifying. Their air cleaning performance potential is excellent and can neutralize even the smallest harmful air particles (0.001 microns). Since ionic air purifiers emit negative ions into the air, they are not limited by air intake restriction, not do they get worse with use. Negative ions also have many benefits on the human body, provided there is enough of them left in the air (after it has been cleaned). They are also very small and portable, making them very convenient to take with you anywhere you go. The maintenance is also very low, usually requiring just a couple of swipes with a cloth.
On the other hand, the performance of ionic air purifiers vastly depends on the number of negative ions they are able to produce. If an air ionizer can not produce millions of negative ions cm3/sec, then it will not be very effective at removing all air pollutants. Many ionic air purifiers also produce harmful ozone as a byproduct, which is especially bad for anyone that suffers from respiratory issues. Such people are more susceptible to even lower concentrations of ozone and should be very careful when choosing the correct air purifier. Another possible downside is that ionic air purifiers can make your walls and furniture dirty. This happens because of the air cleaning process in which gravity pulls down the combined mass of negative ions + air pollutants. These usually deposit on the floor, but some stick on the walls or furniture and can be hard to clean. More on this can be found in my other post here.
Which one should you choose?
Another very important question remains to be answered. Electrostatic vs ionic air purifier – which one should you choose?
While it does eventually come down to preference, all data and research points to ionic air purifiers being a much better choice over electrostatic air purifiers. Even though both of these use the same principle of polarity, electrostatic air purifier just utilized it badly. While they do have some nice advantages like being cost-effective and mostly silent, the disadvantages sadly eclipse those by a whole let.
Ionic air purifiers are the way to go, but you have to be very careful. There are many small aspects of air ionizers that separate good ones from bad ones. The most important thing to look for in an air ionizer is the negative ion emission. In other words, how many negative ions does the machine produce per cm3/sec. From my experience, any emission that is below 6-7 million negative ions cm/3 is too low, even for small rooms. If the product has no information about this number, then you can be sure it is too low – otherwise, the company would happily put it everywhere in the product description. Next, you have to look at the ozone emission. Some air ionizers actually do not produce any ozone at all – they usually come with a higher price tag, which is worth it.
Ultimately, air ionizers are the way negative ions and polarity should be utilized and used to clean the air. Electrostatic air purifiers have a great concept and idea behind them, but the current technology just doesn’t make them as effective as other types of air purifiers.
In case you are in the market for an air ionizer, I have prepared a list of top 5 air ionizers to get in 2020. I made this list while having both the negative ion emission and ozone production in mind. Feel free to check it out and hopefully you will find exactly what you are looking for.
If neither electrostatic or ionic are purifiers sound appealing, then you can always take a look at air purifiers that use the classic HEPA technology for air cleaning. I made a very budget-effective list of top 5 air purifiers under $50, found here.And if you are looking for something more powerful. top 5 air purifiers under $150.
