A Guide to Air Purifiers
An air purifier is a compact device that removes dust, smoke, pet hair and dander, harmful allergens and various other floating impurities from the air. It ensures that the air you breathe is pure.
- Indoor air is 10-30 times more polluted than outdoor air.
- Contaminated with dust, pet hair and dander, particulate matter, soot, microbes, etc.
- Household products, such as deodorants, cleaning products, inkjet printers, etc., also contribute to indoor air pollution.
- According to WHO, 4.3 million premature deaths are a result of household air pollution from multiple sources and poor ventilation.
- 50% of deaths for children under 5 years of age is attributed to poor air quality.
- 13 of the top 20 cities with poor air quality are in India.
- Affects mostly young children and old people.
- Clean indoor air can increase lifespan by up to 5 years on average.
- Clean air can prevent chronic diseases like asthma, lung cancer, pneumonia, allergies, etc.
- Eliminate or minimize source of air pollution
- Improve cross ventilation
- Get an air purifier to cleanse the air
- Ensure kitchen or cooking area is adequately ventilated
- Minimize use of air fresheners
- Dust and vacuum your space regularly
- Eliminate odors instead to trying to mask them
Used indoors, this type of air purifier is capable of cleansing the air in large areas like a room.
Designed to be used in an enclosed vehicle and capable of cleaning the air of pollutants, allergens and dust. Designed to be compact and portable, they usually run on electricity and are plugged into the cigarette lighter receptacle for power.
Every filter technology has the same goal - to filter the air of dust, pollen, odors, smoke and other harmful pollutants. There are different types of air cleaning technologies that you can choose from.
- HEPA (High Efficiency Particulate Air) Filters
- Activated Carbon Filters
- Antibacterial and Germicidal Filters
- Charged Media Filters
- Photocatalytic Oxidation (PCO)
- Electrostatic Precipitators
- Ion Generators and Ozone Generators
- Pre-Filters
- Heat Filtration
HEPA (High Efficiency Particulate Air) Filters efficiently clean allergens such as pollen, animal skin and dander, mold spores, and dust. HEPA filters remove at least 99.9% of all the particles as small as 0.3 microns.
- HEPA air purifier filters have to be periodically changed.
- HEPA certified filters work well for all common particle allergens, but remember not all HEPA filters are created equal.
- The larger the HEPA filter, the more particulate it will be able to remove. The size, material, and construction of the actual filter plays a vital role in the air purifier's performance.
Activated Carbon Filters are rarely used by themselves, but are often used in combination with other filters. Activated carbon/charcoal filters help in absorbing odors and gases thereby neutralizing smoke, chemicals, and fumes.
- Reacts with oxygen to open up millions of pores that are capable of trapping a large amount of gas and odor.
- This makes it the ideal surface for bonding with chemical or vapour molecules.
- Needs to be replaced once they are saturated for optimal performance.
Antibacterial and Germicidal Filters help in eliminating harmful bacteria and germs.
- Using UV filters along with HEPA filters ensures the air you breathe is sterile.
- Used in hospitals, kitchens, labs and daycare schools to minimize the risk of airborne infections.
Charged Media Filters combine a particle filter along with an electrostatic charge filter to capture particles as small as 0.1 microns. They are very efficient in purifying air, but need to be replaced fairly regularly to ensure optimal performance.
Photocatalytic Oxidation (PCO) makes use of a titanium dioxide coated metal plate along with UV light to oxidize and physically break down chemicals during the filtration process.
By doing so larger molecules break down into harmless carbon dioxide and water molecules.
Electrostatic Precipitators function just like charged media filters but instead of using filters to capture particles, the particles precipitate and accumulate on the collector plates.
These plates can be washed clean and do not need to be replaced.
Ion and Ozone Generators clean the air by forcing impurities to cling to nearby surfaces.
The negative ions combine with impurities such as dust and smoke particles and stick to walls and carpets. They may create dirty spots on these surfaces which need to be cleaned.
Pre-Filters, like foam and non-woven polyester, eliminate large particles like pet hair before the next stage of filtration.
- Some have electrostatic properties and use activated carbon to improve filtration and also remove odors and smoke.
- They need to be replaced regularly to increase the air purifiers lifespan.
Heat Filtration: Organic particles like bacteria, viruses, dust mites and mold are eliminated by passing air over an inner ceramic plate that heats up to nearly 400 degree celsius. It works slowly as it relies on convection to keep the air circulating. The main drawback is that it is not effective against chemical vapors, smoke and other non-organic particles.
The ACH (or the air change per hour rate) tells you exactly how many times the air purifier filters the entire room’s air in one hour. If an air purifier that has 5 ACH, it means that the air in the room will be filtered every twelve minutes.
Clean Air Delivery Rate or CADR denotes how efficiently and quickly an air purifier works. It tells you how many cubic feet of air can be filtered in one minute for different categories such as pollen, dust and smoke. Larger rooms will need higher CADR ratings to ensure effectiveness.
When choosing an air purifier, the size of the room is an important factor. Bigger spaces will need larger air purifiers and vice versa. Buy an air purifier that designed to operate in a space that is 20-40% larger than room for optimal performance.
