Air Purifier is a device that eliminates air borne pollutants. Purifiers are normally promoted as being helpful to people prone to allergies and asthma patients. Commercial purifiers are available as small individual units or larger items, which can be fixed to air conditioners or Air Handling Units (AHU); this is normally used in commercial industries.
Commercial Air Purifier
Use of Air Purifier
Air borne pollutants like dust, animal dander, pollen, bacteria, etc causes allergic reactions in sensitive people. Similarly, gas based contaminants and VOCs (Volatile Organic Compounds) also create health risks. With many technology developments, modern air purifiers are very much helpful in eliminating these allergens, and in turn avoiding health hazards. Air purifiers also decrease the need to clean rooms often.
How Does An Air Purifier Work?
Air purifiers have inbuilt ionizers that trap the allergens, thereby cleaning the air. When the ionizer is switched on, power is applied to a sequence of needles built within. This gives rise to a discharge of electrons into the air. These electrons in turn join with the air molecules forming negative ions. These ions are scattered into the room which attracts smoke, dust, chemicals and other allergens, thereby forming bigger molecules. These molecules, being larger in size, are easily trapped by the purifier’s filters. Some of these molecules can also move down to the floor, or append to surfaces charged positively and to the filter of the purifier. The filter thus has to be dusted often.
If the lifetime of the HEPA filter is close to an end, contaminants will not be sieved and will come back to the room. So, the ionizer should not be switched on until the sieve is changed. The lifespan of the filter will come down if the place has contaminants more than the average quantity.
HEPA Air Purifier
Types of Air Purifiers
• Filters: This kind of purifiers decontaminate the air by streaming it through a fine filter. These filters are generally used in houses as a component of air conditioners or heaters. The thickness of these filters decides the size of contaminants that it traps. The denser the filter is even smaller is the size of the particles trapped.
• Ionizing Purifiers: These purifiers use an ionizer that discharges ions when turned on. These ions attach to the contaminants when discharged into the room forming larger molecules which are trapped by the filter used in the purifier.
• Ozone Generators: This works very much similar to ionizing purifiers but changes the air molecules into ozone. Companies manufacturing this kind of generators claim that ozone purifies the air and that it also has health benefits. But there is no substantiation that ozone disinfects air.
• Absorbents: This includes integrating an adsorbent in the purifier to decontaminate the air of smoke, odors and chemicals. It makes use of a process called adsorption wherein one element is trapped on the top of another. The commonly used adsorbent is activated charcoal which has minute nooks to trap smoke.
• Ultraviolet light: Some purifiers use UV radiations that cleanse the air as it goes through thus decontaminating it.
• Industrial Air Purifiers: These are very much expensive and powerful. Such purifiers are used in companies where pollutant free surrounding is required due to its manufacturing process. They use mist collectors, scrubbers, highly dense filters for purification. These are extremely expensive and may cost thousands of dollars.
Ionizers and filters are thus used to purify the air efficiently; filters may have to be changed as and when required.
Video Tutorial:
To develop a better understanding of working of air purifiers, take a look at this video clip.