India houses 13 of the most polluted cities around the globe. This is a stark reminder of the terrible state of the air in the vast Indian cities. Delhi was the subject of headlines across the globe this winter due to smog and the dangers of pollutant levels. According to one study, 4.4 million school children in India have suffered irreparable lung damage as a result of the toxic air. This is for India but when it comes to global air pollution, World Health Organization (WHO) has estimated at 4.3 million premature deaths thus to date are due to household air pollution from a variety of sources and inadequate ventilation.
Incredibly, the levels of air pollution within the house can be 10 times greater than outdoor pollution. The main causes for these excessive levels of indoor air pollution are the use of incense sticks or mosquito coils, in addition to the emissions of cooking products and pet pollen. While the scenario may appear alarming, however, there are ways to reduce the negative impact of the rising air pollution in our homes by using purifiers and filters. ACS (ACS) typically include different types of filters. However, air purifiers are an alternative to tackle increasing indoor air pollution. In the following article, we’ll discuss the various types of air filters that are installed inside air purifiers. AC as well as air purifiers. We will also look at the technology they use and conclude which is superior: an AC or an air purifier.
Different types of filters
Prefilter
Prefilter is often the initial layer of filter installed before the main filter, specifically designed to get rid of large dust particles out of the atmosphere. These filters are generally used to perform the primary job of eliminating dust, pet hair, as well as larger microbes. They are usually composed of foam or nylon and can be washed. They’re found in the majority of Air purifiers, and a few AC brands, such as Blue Star and Daikin. Prefilters, when used in isolation aren’t recommended for those with severe respiratory conditions such as asthma or allergies.
HEPA Filter
You would have probably heard this term (HEPA) if you happen to surf air purifier specifications/details. HEPA filtering is the largest and most significant kind of filter designed to eliminate tiny particles, even those tiny ones. The way to describe it is that HEPA filtering systems are designed to eliminate at the very least 99.97 per cent of an airborne particle that is 0.3 millimetres or greater. Microns refer to one millionth of millimetres. For a better picture, the diameter of human hair is between 50 and 100 um. Humans can’t see anything smaller than 10 microns. The average size of different impurities in the air is as the following:
- Bacteria 0.3-60 microns
- Car emissions are measured in microns of 1-150 microns.
- Spores: 3-40 microns
- Mold 3-12 microns
HEPA filters typically employ two distinct mechanisms to purify the air. There are two or more filters on the outside that function as filters to block the larger particles of dust, dirt and hair from getting through. Inside these filters, the concertina looks like a folded piece of paper. It really is a mat made of extremely large glass fibres. It doesn’t remove small dust particles but instead employs three different techniques to catch dust particles from the air. At high speeds, certain particles can be easily captured when they smash straight into the fibres while other particles cling to the fibres while trying to pass through.
In lower airspeeds, dust particles are likely to move more irregularly across the filters (a phenomenon known as Brownian movement) and could adhere to the fibres of the filter in the flow of random. This allows HEPA filters to trap particles that are larger but smaller than specific limit dimensions (0.3 millimetres).
True HEPA filtering is classified according to the letters A to E, which refers to the degree to which they can absorb particles and resist airflow. The type A filter is the least efficient but they do meet the essential requirements for HEPA and type E (at the opposite end of the scale) are filters that are military grade that can handle biological, chemical, or radiological particles. Based on the characteristics of combustion, they can be classified as fire-resistant (type 1.) as well as semi-combustible (type 2).
It is interesting to note that the HEPA filter was first designed for the nuclear sector to clear radioactive particles that could be harmful to the environment. However, it was later patented to be employed in the air purifiers by Swedish business IQAir. Apart from air purifiers HEPA filters also are employed in aeroplanes, hospitals, and the latest versions of Tesla automobiles.
PM 2.5 Filter
This is perhaps the most essential filter that can reduce indoor air pollution which is air conditioning. According to the World Health Organization (WHO), the levels of air pollutants have dramatically grown in emerging economies that have low or middle incomes, including India. In recent times the effects of air pollution have been proven to be linked to an increase in lung cancer. The dangers associated with pollutant particles are believed to be similar to that experienced by people who have smoking secondhand. This is the reason it is vital to install a PM 2.5 filter to remove micro-sized particles.
The Particulate Matter, PM 2.5 are extremely small particles that are found in the air that are two and one-half microns in size (or smaller). As we have mentioned previously, a micron is a unit of measurement on an extremely microscopic scale, with one inch equivalent to 25 microns. Vehicle emissions and burning oil and wood are the major causes of particles of PM 2.5 particulates.
Then, you may wonder what is the source of PM 2.5?
Ans:
- Fine particles are released from:
- Car
- Bus
- Truck
- Other off-road vehicles
- Minutes of material expelled out of the exhausts:
- Construction equipment
- Snowmobile
- The burning of
- Wood
- Oil
- Fire in the grass
PM 2.5 can lead to major health issues as they traverse the respiratory tract before reaching the lung. PM 2.5 could cause the following health problems:
- Nasal and eye irritations to the nose and eyes
- The lungs and the throat can be irritated.
- Sneezing and coughing
- Reduction in smooth lung functioning
Reputable brands such as Whirlpool, LG, and Carrier among others, have AC models that come with PM 2.5 filters. In actual fact, premium LG ACs are equipped with a specialized sensor that comes with a PM 1 sensor that detects, monitors and alerts users of the PM 1 levels using the application.
Anti-VOC Filter
Due to the increase in pollution in the air we breathe, it has become is composed of various harmful gases and compounds and VOCs are among them. VOCs are volatile organic compounds ( VOCs) are organic compounds that quickly transform into gases or vapours because of their high atmospheric pressure. Midea ACs are equipped with an anti-VOC filter to eliminate VOC. Common sources of VOCs include the combustion of fuels like coal, gasoline, wood natural gas.
The residues of glues, paints and solvents are also a contributor to the amount of VOC in the air. A lot of VOCs pose dangers when they are combined with nitrogen oxides they react with them creating ground-level ozone or smog, leading to warming of the climate. Certain VOCs have been known to cause harm to the kidneys, livers and the nervous system. The anti-VOC filter that is employed within Midea split ACs gets rid of harmful VOCs such as formaldehyde. This ensures that the air is free of these pollutants.
Carbon Filter with Activated Carbon
Carbon filters that are activated are powdered or granular carbon particles that have been processed for being extremely porous. In reality, one gram of activated carbon could easily have a surface of about 100 acres. This means that you are able to benefit from the filtering power of a pinch-sized amount of activated carbon.
Carbon filtering is the process of removing an activated carbon bed that is utilized to remove pollutants and impurities using chemical adsorption. Adsorption is a method whereby organic compounds in the air react chemically with activated carbon, causing them to adhere to the filter. The reaction with oxygen opens up millions of pores that hold a significant amount of gas and smell. The more porous activated carbon gets, the greater contaminants it can trap. These filters are primarily employed to eliminate the multitude of dangerous impurities, such as:
- Smoke
- Chlorine
- Sediment
- Pesticides
- Herbicides
- Organic compounds that are volatile (VOCs)
- Odor
Indian AC brands like Voltas and Blue Star come with activated carbon filters in their air conditioners. The majority of new air purifiers have activated carbon filters and it is essential to use an activated carbon filter because of its inherent ability to snare impurities.
Mi air purifiers include what’s called an activated carbon filter made of coconut which is a useful feature. Coconut shell activated carbon has pores that are mostly within the micropore range (around 85-90 percent). In contrast to meso and macropore that are present within activated carbons from different sources, such as wood and peat, the micropores correspond to the size of the molecules of contaminants found in the air and trap the contaminant molecules. Because of its natural makeup, the activated carbon filter is sturdier in structure and possesses strong mechanical strength and toughness that guarantees long-lasting durability. Blueair air purifiers however include carbon filters that are infused with other chemicals like magnesium dioxide or copper oxide within their air purifiers, to eliminate additional harmful contaminants from the atmosphere, including carbon monoxide and ethylene oxide and Ozone.
Electrostatic Filter
Electrostatic filters are air filters washable that typically do not require a replacement for a long period of time. The filter is utilized in only a handful of Daikin AC models. The electrostatic filter is comprised of multiple layers of vented metal through which air moves. When the air is passing through the initial layer of filtration, air molecules become positively charged because of the tension between the air particles with the filter. These positively charged air particles connect to the next layer while they travel through the remaining filter. While electrostatic filters come with less of a replacement cycle but they require longer to clean an electrostatic filter. Because they use static electricity, the particles that pass through the filter tend to stay inside the line of ducts. This dust accumulation is hard to remove since it is charged with ions and tends to stick on the floor. Additionally, electrostatic filters tend to restrict airflow more compared to other filters. This could mean that ACs will have to work long and hard to cool the space.
Photocatalytic Filter
A lot of air purifiers and ACs include Photocatalytic filters. The catalyst used in the filter that removes pollutants from the air is usually titanium dioxide, which is nothing more than a semiconductor (like silicon). It is stimulated with ultraviolet (UV) light, which is a short wavelength that is part of the electromagnetic spectrum that isn’t visible to our eyes. There isn’t much titanium dioxide is employed in this filter, it’s a thin layer that covers the surface of the substrate. The substrate is typically constructed of ceramic or metallic material (such as aluminium).
When the UV light hits titanium dioxide and the titanium dioxide is heated, electrons (negatively charged particles in the atoms) are released from the surface. The electrons do the job of filtering air. The electrons interact with water molecules (H 2O) in the air, and break down into the hydroxyl radicals (OH*) that are highly reactive, short-lived and uncharged forms of hydroxide Ions (OHand OH). These tiny quick hydroxyl radicals attack larger organic (carbon-based) pollutant molecules, breaking up the chemical bonds. The pollutant molecules that react post-reaction are transformed into relatively harmless substances like water and carbon dioxide. This is an excellent example of oxidation. That’s why air purifiers that operate in such a way advertise their purification using PCO-based technology (photocatalytic oxygenation).
The main drawback to the photocatalytic filters is that they also release tiny quantities of Ozone (O 3)–a chemical form of oxygen that is an air pollutant. It is therefore recommended to stay clear of buying products that utilize photocatalytic oxidation since it creates ozone in the air in your home, which is not a good idea for air purification. Additionally UV sterilization is not advised for indoor use as it could cause sunburns and is only suitable for locations with minimal human presence.
Nano Silver Filter
Indian AC brand like Voltas and BlueStar includes nanosilver filters in their latest ACs. Nano silver filters constantly release silver ions to disinfect the bacteria. This silver-ion filter does not just kill bacteria in the air but also blocks it from growing microbes, such as bacteria, viruses and spores, as well as fungi. They alter their internal structure by absorbing the cell’s elements. If you have pets or suffer from allergies during the season, a nano silver filter could prove effective due to its capacity to eliminate pet dander dust and pollen. The manufacturers claim that it eliminates 600or more types of bacteria which leads to 99.99 percent elimination of the air that is filtered. On the other hand, Friends of Earth Germany the environmental watchdog has condemned the use of silver nano because of the negative effects on different types of cells.
Anti-bacterial Filter
The majority of AC filtering systems and air purifiers include one or another type that is anti-bacterial. However, their names and design may differ. Some refer to it as anti-bacterial, others call it anti-microbial, and others refer to it as a biofilter. Anti-bacterial filters work well to clean the air of harmful microorganisms, and also impede their development. The filters utilize a microstructure charge that catches pollen dust, mildew smoke, and mould spores. The charge draws in other microorganisms that are in the air, while the network of fibres effectively keeps the airborne particles.
AcaroThe Bacterium Filter employed within Voltas AC captures ticks, mites, and other microorganisms which are harmful to human beings. They also possess antiseptic properties within the filter that eliminates harmful bacteria, thus keeping a healthy and clean environment within the room that is air-conditioned. The antibacterial filters employed for Blue Star ACs eliminate 95% of Escherichia Coli and Staphylococcus Aureus bacteria, which are known for causing infections, boils and diarrheal illnesses. Biofilter that is used in Carrier ACs detaches microbes that are airborne, as well as bacteria and fungi.
Anti-bacterial filters offer a constant stream of fresh air throughout the space. The good thing is that they can be easily cleaned using the use of a vacuum cleaner, or by hand washing.
Catechin Filter
Japanese AC manufacturers such as Toshiba, Panasonic, and Mitsubishi have a large use of Catechin filters in their latest ACs. Catechin filter filters are extremely effective in getting rid of unpleasant smells. Catechin filters are derived from an antioxidant that is naturally found in green tea. They block the flow of pollutants that cause odours, such as smoke from cigarettes and pet smells because of their anti-bacterial and anti-dust properties. A further benefit is that they capture and kill microscopic bacteria as well as viruses that can result in cough, cold and other respiratory ailments. In line with Japanese brands, Indian AC brands like Voltas and Blue Star have begun using Catechin filters in their ACs to remove household smoke and other contaminants.
Vitamin C Filter
There are a few AC models of brands such as Blue Star, Midea, and Voltas that come with Vitamin C filters. Sounds nutritious? Manufacturers claim it is because the Vitamin C filter provides your air with vitamins C which helps to soften the skin, eases stress, and offers therapeutic benefits.
Vitamin C is vital to synthesising substances that are essential in maintaining healthy skin. Incorporating vitamin C into the air conditioner’s airflow is designed to provide an emollient effect on the skin. To incorporate vitamins C and airflow an additive made of ceramic in this filter releases vitamin C when there is a lot of air moisture. Zeolite, a water-absorbing material is added to offer an ongoing production of Vitamin C during dry conditions in winter when moisture is crucially required. Manufacturers also claim that this filter can last for several years without needing replacement.
Do You Really require the air Purifier or an air conditioner? enough?
The main question is do you really require an air purifier, or is it better to get an AC that has a good filtering system? This is an issue that is difficult to provide an answer that is general. Because it is based on many variables. If you are in a village or town, and you believe that the air pollution in your home is not shockingly high, like in cities, it is advisable to opt for an AC that has a reliable filtering system. If that is the case, PM 2.5 filtering is essential and several major manufacturers offer that. In actual fact, LG has launched new models that also detect PM1 levels within the room, in addition to providing filtration for particles of PM 2.5 pollutants. If you live in a city that is large or suspect that your indoor air pollution is greater due to the proximity to an industrial site or construction site, then you need to consider an air purifier specifically designed for you. Make sure that the purifier you choose to purchase has a HEPA filter, not HEPA-type or HEPA-like filters that are not regulated and are cheap replicas of HEPA filters. It is important to remember that ACs don’t have HEPA filters and it’s virtually impossible to alter the AC filtering system to include HEPA filters. HEPA filters remove extremely tiny impurities that are less than 0.3 um. If they are utilized in ACs they can cause various complications, including:
- Airflow is reduced
- More expensive maintenance costs
- Leaks
- A premature breakdown
- Overheating
Therefore, it’s better to select an air purifier equipped with a genuine HEPA filter rather than relying on to rely on the AC filter to cleanse the indoor air pollution when the air quality is at dangerously high standards. Make sure that air purifiers come with activated carbon filters that eliminate the fumes, smoke and other odours that are foul. It is advised to avoid air purifiers using photocatalytic or electrostatic filters since when they are filtered, they create ozone that damages the environment. Although AC filtering and purifiers may be used to treat tiny particles such as dust, dander, or even allergens and bacteria, they are not able to shield the user from harmful chemical gases such as carbon monoxide, carbon dioxide, nitrogen dioxide, etc. This is why you should consider the natural alternatives of keeping plants like areca palms or money plants that are known for their purifying properties.
