What is in an air purifier ?

An air purifier is a device which removes contaminants like bacteria, virus, allergens (trigger allergies in sensitive people), pollen, pet dander, mold spores, smoke particles, volatile organic compounds (VOCs), & dust from the air. Air purifiers are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke but with the increase of pollution levels, mainly in metropolitan cities, it is advisable for everyone.

What are some common air purification method ?

Most air purifiers utilize common air purification technologies such as HEPA, Activated Carbon, Ionizers, and UV bulbs, and these methods are usually categorized by filter type:

Mechanical Filters such as HEPA and Activated Carbon force air through a mesh that traps particles.
Electronic Filters such as ionizers use electrical charged to attract and deposit allergens and irritants onto electrostatically charged plates.
Hybrid Filters contain elements of both mechanical and electrostatic filters, and many air purifiers use this type of filtration method.
Gas Phase Filters remove odors and gases, but do not filter out particulates.
UV Sterilization involves the use of UV light, which damages the DNA of microorganisms and bacteria.

How does an air purifier clean air ?

Air purifiers clean the indoor air by drawing the polluted indoor air into the unit and trapping the particles, allergens and contaminates onto a filter. Air Purifiers use different technologies to clean air as different kinds of pollutants need different kinds of purification.

PCO technology / Photocatalyst Filter

Photocatalytic oxidation (PCO) uses a titanium dioxide plate (TiO2) irradiated by intense ultraviolet light. This produces hydroxyl radicals capable of breaking down smaller particles, chemicals, and odors. These particles become either CO2 or water vapor. No filters are necessary for photocatalytic systems, however filters are usually added to capture larger particles and protect the semiconductor plate from residue buildup that can reduce effectiveness.

Photocatalytic oxidation, or PCO, was developed and used in space technologies for both air and water purification. PCO involves photocatalysis, and in chemistry, this process involves the acceleration of a photoreaction in the presence of some sort of catalyst – namely catalyzed photolysis and photogenerated catalysis. While this may seem somewhat complicated, the PCO process used in PCO air purifiers is quite simple and effective, and involves the following steps:

A metal surface coated with a metal light is irradiated with UV light to produce hydroxyl radicals and super-oxide ions.
These radicals and ions break the molecular bonds of chemicals (such as formaldehyde and toluene) they come into contact with and slice them into smaller compounds.
These compounds are then further broken down until only carbon dioxide and water vapors are left.

Essentially, a PCO air purifier uses short-wave UV light to sterilize and kill up to 99.9% of bacteria and viruses, and independent research has also confirmed its effectiveness in eliminating contaminants such as bacteria, viruses, mold, and VOCs.


Indoor air is full of particles, and in fact, most of the mass in the particles is in the larger particles & not in the tiny pollens. In absence of a pre-filter in any Air Purifier, the high-efficiency, more expensive HEPA filters will clog up with big particles too quickly. Even though HEPA filters have a large number of pleats which gives them lots of surface area, they can fill up more quickly if the larger particles are not pre-filtered out. In a typical family, with kids, dogs or cats, and a lifestyle that’s highly active, an air purifier has to deal with a lot of large particles.

Pets are not the only ones with dander. Our customers using an air purifier for the first time are typically surprised at how much human hair is caught in the pre-filter.

That’s one of the main reasons that the pre-filter on your air purifier should be changed, or at least checked according to the prescribed schedule.

High-Efficiency Particulate Air (HEPA Filter)

High-Efficiency Particulate Air or HEPA is a type of air filter. HEPA filters were originally developed by the Atomic Energy Commission to capture radioactive dust pollen. Filters that are awarded the HEPA accolade are used in various locations, whether in medical facilities, automotive vehicles, airplanes, home filters, or wherever very pure air is sought. The filter must satisfy certain standards of efficiency such as those set by the United States Department of Energy (DOE). To qualify as HEPA by government standards, an air filter must remove 99.97% of all particles greater than 0.3 micrometer from the air that passes through.

HEPA filters trap small particles that may cause problems for allergy sufferers and others with health problems. Reducing or eliminating those particles will make cleaner air at your home & at your work place.

Alveolate Activated Carbon Filter

Carbon filtering is a method of filtering that uses a piece of activated carbon to remove contaminants and impurities, utilizing chemical adsorption.

Each piece of carbon is designed to provide a large section of surface area, in order to allow contaminants the most possible exposure to the filter media. One pound (454g) of activated carbon contains a surface area of approximately 100 acres.

This carbon is generally activated with a positive charge and is designed to attract negatively charged water contaminants. Carbon filtering is commonly used for water purification, but is also used in air purifiers.

Carbon filters are most effective at removing chlorine, sediment, and volatile organic compounds (VOCs) from water. They are not effective at removing minerals, salts, and dissolved inorganic compounds.

Spongy Activated Carbon Filter

The active carbon filter works by a fan, transporting air through the active carbon filter. On its way, the air must pass through the active carbon inside the activated carbon filter. Then the spongy active carbon absorbs the molecule of odour. So the air comes back out clean.

Antibacterial and Mildew Proof Filter

Antibacterial and Mildew Proof Filter prevents bacterial, fungi and mildew from growing.

UV light

UV Sterilization involves the use of UV light, which damages the DNA of microorganisms and bacteria.

Unlike filters, which collect pollutants as they pass through the purifier, the purpose of ultraviolet lights in air purifier is more specific: they are meant to kill organic matter, such as bacteria, mold, and viruses. Thus the Environmental Protection Agency refers to air purifiers that use UV lights as “Ultraviolet Germicidal Irradiation Cleaners,” the term “germicidal” meaning “germ-killing.”

The principle behind UV air purifiers is fairly simple: UV radiation in sufficient doses is deadly to many living things, including some that are common constituents of indoor air pollution. When these objects pass through the purifier, they are exposed to the UV radiation released by the light, and as a result, they are destroyed.

Use of UV light is very popular in Water Purifiers. There also, the purpose of UV light is to remove organic matter from the water & making it consumable.

Negative Ion

Negative ions are negatively-charged electrical particles that are magnetically attracted to allergens and other airborne contaminates, which are positively-charged. The newly-formed larger particles are then able to fall harmlessly to the ground, and out of the air we breathe.

What is a HEPA filter and why it is popular ?

HEPA filters were originally developed by the Atomic Energy Commission to capture radioactive dust pollen, and by definition, a true HEPA filter must be capable of removing at least 99.97% of particulates as small as 0.3 microns such as dander, dust, and pollen. These filters are popular because of their superior filtration abilities.

How do air purifiers that do not have air filters,clean the air ?

Negative ion and ozone air purifiers clean the air inside the same way nature does outside, by emitting the world’s most powerful and pure air-cleansing agents: negative ions and moderate amounts of ozone.

What are the standards for air purifier performance ?

There are no official standards to measure an air purifier’s performance at this time, and the FDA has repeatedly asked groups of experts to recommend such standards. Nonetheless, the Association of Home Appliance Manufacturers (AHAM) does conduct independent tests which measure an air purifier’s Clean Air Delivery Rate, or CADR.

What does the CADR rating mean ?

To clean an entire room, all of the air in the room needs to pass through the air cleaner’s filter. Air cleaners are rated by the amount of air moving through the filter. This rate is called CADR or Clean Air Delivery Rate. CADR measures the amount of particle-free air being delivered into the room. The higher the CADR, the larger the room size that an air cleaner can be cleaned.

How is CADR measured ?

CADR determines how much clean air an air purifier delivers to a room, and this is measured in cubic feet per minute. Air purifiers are usually tested on their ability to remove three types of common pollutants: smoke, dust, and pollen. If an air purifier has a CADR rating, this measurement is usually found on the packaging.

How to select the right air purifier ?

What factor should one consider before buying an air purifier ?

An air purifier is a long term investment you can make given that an average device comfortably lasts for many years. When buying an air purifier, you could consider the following factors:-

a. What is your primary air purification need?

In most cases, a general purpose air purifier would resolve majority of your problems. Typical air purifiers from Atlanta Healthcare are effective against all forms of air pollutants and work effectively in heavily polluted urban air conditions.

b. What area do you want to cover?

The floor area (in most residential scenarios) is an important parameter in choosing the right air purifier for your needs. Atlanta Healthcare’s air purifiers are designed to address the widest possible range of floor space with Tornado Pure, Alfa 351 and Gama 331 being entry level models for small-medium sized rooms and Gama 501 and PureZone 651 being for larger rooms upto 500 Sq. Ft.

For industrial purposes and for usage in offices, much larger space needs to be addressed and this segment is catered to by the PureZone 1001 series.

c. How good is the product’s technology?

This is a subjective decision you need to take. As we have described in our Technology page, Atlanta Healthcare has by far the most advanced air purification technology in the industry. We use the finest quality materials in making them and provide excellent service and support.

d. How much noise does the machine make?

Most air purifiers in the market trade off effectiveness against noise levels. Our products are designed after several years of research to optimize the ‘air flow’ levels for effective purification without making much noise. At 50 db, our products are by far the most silent devices in the market.

e. How easy is it to install the product and how portable is the product?

Ease of installation and portability are key concerns most of our customers have which is why we have fine-tuned our designed to be ‘plug-n-play’ using regular 5 Amps socket. Except for the heavy duty PureZone 1001, all our other products weigh less than 14 Kgs which make them easily portable.

These are some simple parameters you can use to select the right product for yourself. However, if you have more specific needs, feel free to reach out to us via email or phone. Our experts will be happy to assist you.

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KLAIRON TECHNOLOGIES PVT.LTD. G-5, PUSHKAR ENCLAVE, PASCHIM VIHAR, New Delhi-110063, India Call @ : +91-9873646000