Types of Air Purifier to Consider Before Buying

We’re all concerned about safe water and spend a lot of money for water purification. But are we feeling concern about safe air? No, not feeling worried as much as safe water.

It’s because drinking water takes some conscious actions where breathing air doesn’t. And you realize that air is as important as water, right?

If we both agree on YES for the question above, we should now get some knowledge on air purifiers. Air purifiers make the air in our living place and workplace safer to breathe.

Before buying an air purifier, knowing the popular types of air purifier and their pros cons makes a big difference. So, let’s start.

Understanding The Types of Air Purifier

To categorize air purifiers, we can divide the whole group into 2 main categories. One is called Active purifier and another is called Passive purifier.

Active purifier uses ionizing techniques to kill harmful microbiological particles. No filters are used. So, these are used in junction with purifier filters.

Passive purifier uses air filters to catch and remove particles from the air. These purifiers can’t kill bacteria or viruses. So, a passive purifier can be more effective if it’s used in junction with an active purifier.

Let’s see the filtering techniques that are used in our air purifiers both residentially and industrially.

1. Thermodynamic sterilization technique (Active)

Thermodynamic sterilization works on the basis of the idea that heat can kill everything. With 200°C or 392°F, this purifier can incinerate 99.9% microbiological particles like bacteria, viruses, dust mite allergens, mold, and fungus spores.

The heated air then passes through ceramic cores to cool down. This purifier purifies by killing germs but it doesn’t remove those germs by filtering. It creates partial thermal byproduct while operating.


  • Kills germs and viruses effectively with heat treatment
  • Reduces ozone in the room


  • Does partial thermal decomposition
  • Doesn’t remove particles from the air

2. Ultraviolet germicidal irradiation technique (Active)

Ultraviolet germicidal irradiation or UVGI technique works by sterilizing the air that passes through the UV lamps. This one also can’t remove the dead microorganisms by filtering. All it does is kill those with ultraviolet rays.

This technique isn’t used in a purifier all alone. With other filtering techniques that can remove particles from the air, this technique of air purifying is very effective. Placing the lamps in the duct system or air cooling system makes the air safe to breathe.


  • Kills germs and viruses effectively with UV light
  • Doesn’t create ozone in the atmosphere


  • Can’t remove particles from the air

3. Polarized-media technique (Active)

Using 24-volt DC voltage, the polarized media technique can successfully collect the ultra-fine particles. The DC voltage creates a polarized electric field to polarize the particles. Then, those charged particles are collected on a disposable media pad.

By repeating the process, again and again, no single particle is left to do any harm. The non-ionizing property creates no ozone during the process. Another great advantage is the filter gets more effective as it catches more particles from the air.


  • Kills germs and viruses effectively with polarization method
  • Odor and VOC molecules are collected
  • Less maintenance is required


  • Might or might not create ozone

4. Photocatalytic oxidation technique (Active)

Photocatalytic oxidation or PCO, in short, is a technique where organic contaminants are oxidized and degraded. This way your air gets safer to breathe and it also saves energy to a great deal. The technique is used commercially and costly than others.

There was a concern for creating formaldehyde as a byproduct but recent developments show that the harmful byproduct exists no more. This is not a filter that removes particles rather it sterilizes the air. This type of air purifier requires regular maintenance for smooth operation.


  • Kills germs and viruses effectively with oxidization method
  • Saves energy to a great deal


  • The technique requires other air purifying filter for maximum purification

5. Ionizing technique (Active)

An ionizing technique to purify air is very interesting. It creates electrically charged air or gas ions by using an electrical surface. Then, the harmful particles get attached to these ions and another charged collector plate collects them.

A fan-less ionizer works quietly but is less efficient than a fan-based ionizer. Other than many benefits, it creates ozone and other oxidants as a byproduct but the amount is very low.


  • Catches germs and viruses effectively with the ionizing method


  • Creates ozone and other oxidants as a byproduct

6. Using ozone generator (Active)

Simply ozone generators generate ozone at massive scale. Breathing ozone gas is very harmful. Yet, there are different uses of this technology. It is used in such environment where no living creature is present.

The ozone generator is very effective in removing smoke odors after fire damage, toxic molds, and musty smells after flooding, and the stench caused by decaying flesh.


  • Successfully removes any odor or toxic fumes


  • Creates ozone which is very harmful to health

7. Using purifier filters (Passive)

The air purifiers using filters can remove large particles from air effectively. The standard for making air filtering system is called HEPA which is 99.97% effective against anything larger than 0.3 microns. While filters can remove particles, they can’t deal with bacteria, virus, mold, or odor.


  • Catches and removes particles using filters
  • No harmful byproduct and good for allergy patients


  • Can’t remove odor or ultra-fine particles

8. Using active carbon (Passive)

The lack of removing volatile chemicals on a molecular basis for HEPA filters is covered by another passive filter named charcoal or active carbon filter. Absorbing chemical with carbon has an alternative but costs more than using charcoal.


  • Removes gases using an activated carbon filter
  • No harmful byproduct


  • Can’t work alone, has to be used in junction with HEPA filter

Final verdict

The discussion above has made you understand that no technology alone for air purifying is sufficient. Based on pollution level and type in your area, 2 or more types of air purifier combined in a single purifier works most effectively.

So, don’t stop reading and knowing some stuff on air purifying. There are other great articles and honest product reviews on our website for your interest.