Are photocatalytic air purifiers worth their price?
Air purifiers with a photocatalytic function are considered the most modern, efficient and economical, is this true? The main advantage of photocatalysis is the complete decomposition of toxic pollutants present in the air to safe water, oxygen and carbon dioxide. In contrast, appliances with carbon filters simply trap pollutants in the filter pores, and are not capable of capturing all particles. Photocatalytic cleaners destroy particles as small as 0.001 microns. These are the smallest gaseous substances that are present in the air.
Let’s start with the main thing: photocatalytic air purifiers are very effective in dealing with harmful impurities such as tobacco smoke, volatile chemical compounds, carbon monoxide, exhaust fumes, bacteria, mold, dust mite and even viruses. For example, viruses are so small that no mechanical filter can hold them and they can only be destroyed chemically, which is what photocatalysis does.
Photocatalytic devices are 500 times more effective than models with charcoal filters for removing unpleasant smells and various gases, not for nothing they are considered the most perfect cleaning systems at harmful industrial production, where removal of toxic gases is vital. So why is it that coal filters, so well known to everyone, are as much as 500 times weaker than photocatalysis? Carbon absorbs odor molecules into the micropores on its surface and over time loses its properties, gradually clogging up. Moreover, coal pores have time to absorb not all the particles of gases and odors, many of them are so light that they simply fly by. The secret of the photocatalytic cleaner is in the production of active oxidizers, which react chemically with harmful substances, decomposing them into simpler, safer elements. At the same time the photocatalytic filter will be as effective as possible throughout the life of the unit, as the catalyst is not wasted in any way. You will only need to replace the UV lamp every 1-2 years.
For a device with photocatalysis there are no half-measures, if it is turned on, there are no impurities in the air – neither large nor microscopic; neither light (gases, smoke) nor heavy (bacteria, mold); and it does not matter what chemical composition they have.
When using photocatalytic air purifiers at home or in the office the air is freed from microorganisms and allergens of organic origin, such as dust mite and mold, which is very important for allergy sufferers.
Oxidative processes of photocatalysis are so strong that 99.99% of all airborne viruses, bacteria and microorganisms are destroyed.
Effectiveness of removing odors through photocatalysis – 85% during the first 5 minutes of the device, ie, a few minutes after turning it on you will no longer have to breathe tobacco smoke, formaldehyde and other toxic substances that destroy health.
What kind of air pollution a photocatalytic air purifier can cope with:
- Any unpleasant odors. Almost all odors are formed by organic compounds, so they easily decompose and disappear.
- Smoke including tobacco smoke, soot, smoke, smog
- Harmful toxic substances: carbon monoxide, formaldehyde, ammonia, nitrogen oxides, hydrogen sulfide, phenols, exhaust fumes
- Toxic organic compounds: Chlorine, esters, hydrocarbons (e.g., fumes from household cleaners)
- Allergens: Dust mite feces
- Disease-causing viruses, bacteria
- Various microorganisms: mould, fungi, dust mites
According to the results of recent studies, appliances with charcoal filters do not cope with light compounds – formaldehyde, nitrogen oxides, carbon monoxide – the most typical urban air pollutants.
For example, formaldehyde is emitted from furniture, building and finishing materials. It impairs the respiratory and nervous system. Carbon filters cannot clean the air from formaldehyde, but photocatalytic filters effectively deal with any toxic fumes.
Non-coal and charcoal filters are also ineffective against bacteria, viruses, micro-organisms living in the air of most rooms, provoking the emergence of diseases. If the design of the device does not provide an ultraviolet lamp, the microorganisms detained by the filter, often continue to multiply on it. Photocatalytic cleaner with the formed oxidants damages the outer shell of microbes, as a result they die, and the air is disinfected. Such devices destroy even the most dangerous microbes for humans: E. coli, Staphylococcus aureus and mold.
How photocatalytic air purifiers work:
A photocatalytic filter consists of a catalyst and an ultraviolet lamp, it is their interaction that produces such a powerful purification. The ultraviolet light hits the surface of the catalyst (in most cases it is titanium dioxide) which produces natural substances with a high oxidative capacity (ozone and higher oxides) which decompose all the pollutants on the surface of the catalyst. In addition, penetrating into the air of the room, oxidants encounter pollutants, interact with them, decomposing them into harmless substances (mainly water and carbon dioxide). Decomposition occurs at the molecular level. Thus, a photocatalytic purifier does not accumulate anything anywhere, you do not need to change the filter itself, the air becomes clean in a completely natural way, as it happens in nature.
Photocatalysis is an environmentally friendly and completely harmless method of purification because it copies the natural photochemical processes that continuously purify the air in nature. Photocatalysis was discovered more than 20 years ago, but photocatalytic devices began to be mass produced not so long ago.
In the 90’s there were experiments in air purification:
- In apartments and tunnels in Japan.
- In a microelectronics production facility in the US
- An explosives manufacturing plant in the USA
- The cabins of Boeing airplanes and Japanese cars
- In hospitals in the treatment of allergies and asthma in the U.S. and for the destruction of pathogenic microflora.
At that time, the effectiveness of photocatalysis was proven experimentally.
Advantages of photocatalytic air purifiers:
- No replacement filters, i.e. additional maintenance costs for the device. Only the UV lamp is replaced 1-2 times a year. As a result, after years of use a model with a charcoal filter will cost you the same or even more.
- Contaminants decompose completely, do not accumulate anywhere, pathogenic microflora, which can become a source of infection, do not multiply in the filters
- Photocatalysis is the most effective method of removing light pollution that rises quickly to the ceiling – smoke, odors, toxic gases.
- Low power consumption – no need to filter the air through thick filters
- High efficiency of 99,99% for elimination of microorganisms, bacteria and viruses
- Environmentally friendly and safe – photocatalysis copies the natural processes
- Effective removal of allergens – mold, dust mite and its excrements
- Low maintenance – you need to vacuum the filter about once in six months.
But like any thing photocatalytic air purifiers have their pluses and have their minuses. what are their disadvantages? Photocatalysis copes well with chemicals, odors and organic contaminants, but is completely powerless against particulate matter: dust, pollen, hair, etc. That is why most devices also have a hepa-filter.