For people with allergies, families with small children or people living in urban areas, an air purifier is almost a standard equipment. But while more and more people are buying them, there is also a lot of misunderstanding about what the air purifier actually filters out and what it doesn't. In this article, we'll explain how an air purifier works, what it really filters out, what it doesn't, and where the role of regular air conditioning maintenance comes in.
How does an air purifier work?
The basic principle of an air purifier is simple: the fan of the device sucks in the air from the room, passes it through a series of filters and then blows the purified air back into the room. Most household air purifiers use a combination of the following filter technologies:
- Pre-filter - catches larger contaminants (dust, lint)
- HEPA filter - designed to filter out fine particles
- Active charcoal filter - to trap certain odours and gases
- Occasionally ionising or plasma technology
The efficiency of the appliance is affected by several factors, such as the quality and condition of the filters, the air delivery rate (m³/hour) and the size of the room.
What does the air purifier actually filter out?
Now let's look specifically at what the air purifier filters out
- Fine powder: a good quality HEPA filter can remove most of the microscopic particles suspended in the air. This includes urban smog and fine dust. This can be particularly useful in metropolitan environments.
- Pollen and allergens: the air purifier really shows its power during allergy season. Pollen, dust mite droppings and other microscopic allergens can be effectively filtered out with a proper HEPA filter.
- Certain bacteria and viruses: a good quality HEPA filter can also trap some of the micro-organisms suspended in the air. However, it is important to stress that this is not sterilisation. The air purifier reduces the concentration in the air, but does not „disinfect” the room.
HEPA ≠ omnipotent
Many people think that having a HEPA filter in an appliance solves all problems. But this is a misconception. A HEPA filter is excellent against particles, but it does not break down gases or remove carbon dioxide, so it is not a substitute for ventilation. The operation of an air purifier is optimised for particle filtration, but air quality is more complex.
What does the air purifier not filter out?
Now we come to the lesser-known part.
- Carbon dioxide (CO₂): is one of the most common misconceptions. An air purifier does not reduce CO₂ levels. Carbon dioxide concentrations can only be reduced by introducing fresh air. If there are more people in a closed room, the air is „used up”. Even if the air purifier works, the CO₂ level will rise. The only solution is ventilation or a heat recovery ventilation system.
- Volatile organic compounds (VOCs): compounds from paints, furniture boards, cleaning products are present in the air in gaseous form. Activated charcoal filters can trap some, but not all compounds are effectively treated, so they are not a complete solution.
- Internal contamination of the air conditioning system: This is a particularly important aspect. The air purifier filters the air in the room, but if the air conditioning not maintained, then mould can develop, bacteria can adhere to the indoor unit. The use of an air purifier does not replace the need for air conditioning maintenance.
An air purifier and an air conditioner are an excellent complement to each other - with proper maintenance.
Allergy sufferers: what to look out for?
The allergy symptoms many people buy air purifiers to reduce the amount of air pollution. This can be a good choice, but it is also important to change the filter regularly and to clean the air conditioner at least twice a year.
SMARTAIR's approach to indoor comfort is based on three pillars:
- properly sized equipment
- regular maintenance
- conscious use
An air purifier can be a useful tool here, but it is not a substitute for maintenance.
Summary
Air purifiers work effectively against particles, but indoor air quality is more complex. If you want really clean, healthy air in your home, you need to think in terms of a system: proper air conditioning, regular cleaning, supplemented by an air purifier if necessary, and proper ventilation.