Concerned about Coronavirus and the quality of the air that you breathe? Please read the post titled Air Filtration: Make COVID-19 A Never Event.
When the topic of air purifiers comes up, the first two questions most people have are: “Do they work,” and, “do I need one?”
Air purifiers can seem mysterious. It’s not immediately clear what it actually means to purify air and many people live healthy lives without an air purifier.
In this post, we’re going to take a deeper look at air purifiers. How do they work, what they can do and whether you really need one?
How do Air Purifiers Work?
Let’s start with the basics. An air purifier is a way of removing particles from the air, whether that’s dirt, dust, smoke particles, mould, bacteria, pollen or animal dander.
Within the air purification market, there are four common types to clean air.
1. Air Filtration
The first type of purification is simple air filtration. Air from the room is passed through a sieve (or membrane) and particles are trapped within the purifier. The filters can be made of glass fibres, plastic fibres, cotton fibres or ceramic membranes.
One of the most common filters is the HEPA filter, made of borosilicate glass fibres and plastic fibres. It removes particles measuring 0.3 microns and above with an efficiency of 99.95% or higher. One of the challenges in these Pandemic times due to coronaviruses is the shortage of supply for HEPA filters.
On the other hand, some air filters, such as our own Smart Air air purifier, go further beyond simply trapping particles. Smart Air uses a ceramic microfilter that is coated with a nanomaterial, inactivating and destroying particles such as viruses, bacteria and mould.
2. Electrical Attraction
The second type of purification is electrical attraction. The basic principle here is to generate an electrical charge that attracts particles and either bring them towards a collection plate or puts them through a filter.
You will sometimes see these types of air purifiers as ‘electrostatic precipitators’. Typically, these purifiers are used in industrial and commercial settings such as kitchens.
3. Air Ionisation
Air ion generators also rely on electrical charges. These devices work by releasing negatively charged ions into the air and attracting positively-charged ions. This causes dirt, bacteria and pollen particles to get heavier and fall to a nearby surface or a charged collection plate.
A lot of the scepticism behind air purifiers comes from air ionisation as there is limited evidence to suggest they effectively remove particles from the air.
4. Ozone Generation
The fourth type of air purifiers is ozone generators. High-voltage electrical currents are used to convert oxygen to ozone, which then breaks down various particles and molecules in the air.
It is claimed that they can destroy odours, mould, particles and bacteria. However, this comes with the caveat that they produce ozone: a gas that is toxic to humans. Ozone generators are typically reserved for use during renovation or when cleaning up after a fire or flood.
Why are there so many types of air purifiers?
The previous section only covered some of the most popular air purifiers. There are many more techniques, combinations and styles.
The reason so many exist is because they fulfil different purposes and needs.
Filtration is typically the most effective form of air purification with many models using HEPA filters and removing upwards of 99% of particles with diameters of 0.3-microns and above. Yet, there are downsides:
- They are often not reusable and need replacing on a relatively frequent basis (replacing them is actually an important aspect, as many air filters can actually become a health hazard if filters are not replaced according to the manufacturer instructions).
- They can take a while to process large quantities of air.
- They do not treat the air of gaseous pollutants and may not be efficient in removing viruses.
- They can be expensive to buy and to maintain, although you’ll find a wide range of solutions in the market, from relatively inexpensive and small models to large, complex and expensive systems.
- There is currently a shortage in supply to address the crisis we are now facing as a result of Coronavirus.
However, there are alternatives to HEPA filters. Ceramic filters can provide effective air purification but also do not need to be replaced regularly and can be treated with a nano-coating to target viruses and odours. This would also alleviate the waste to landfill that is caused due to the need for replacing and discarding HEPA filters.
Electrical attraction has the benefit of attracting particles towards them and many don’t require you to change their filter. However, effectiveness can vary. Ion generators can cause particles to stick to walls and furniture, leaving a stain.
Ozone generators can be useful for purifying the air with more serious pollution such as buildings with lots of smoke particles after a fire. Nevertheless, they do produce ozone, which is harmful to health when inhaled.
What Are the Benefits of an Air Purifier?
There are many potential benefits of air purifiers but here we’ll look at the four most common uses within homes and workplaces.
Removing Allergens
Air purifiers do a fantastic job at removing common allergens from the air, including pollen, animal dander and dust mites.
These are some of the most common allergies and when properly used, an air purifier can help sufferers in their own home and potentially help alleviate some of the symptoms associated with their allergy.
For asthmatics and people with other respiratory conditions, removing particulate matter like the ones described here can be very beneficial.
Keeping a Space Clean
Air purifiers remove a considerable amount of dust from the air we breathe and will help to stop the dust building up around a home or office. However, they are not an alternative to cleaning.
They can stop new particles entering your space but, depending on the type of purifier, they may not be effective at removing particles that have already settled and may not do much if you regularly bring lots of new dirt or detritus into the area.
Fighting Disease
Depending on the type of purifier, they can be used in various capacities to fight disease and illness.
Many purifiers are able to remove mould spores and bacteria from the air, helping to keep food preparation spaces more hygienic and slowing down the buildup of mould.
Others have more robust applications in healthcare. Air ion purifiers claim to have had success at capturing dangerous bacteria and at preventing the transmission of airborne influenza viruses. Yet, these findings are disputed by some researchers who have not found air ionisers to be consistently capable of helping people with respiratory ailments.
Air purifier filters are also capable of fighting viruses and bacteria. One common method is to combine the air filter with UV light in order to kill bacteria and viruses; however, their effectiveness depends on the length of exposure and this process can produce ozone. An alternative is the use of nanocoatings that can inactivate viruses on contact and do not require a UV light source.
Removing Odours
Air purifiers can help to remove odours but their success will depend on the features of the purifier.
Nearly all purifiers can remove some of the bacteria and particles that will cause odours but some particles that cause lingering odours can be very small and stubborn.
To get at odours caused by things such as cigarette smoke or frying oil, a purifier needs to be combined with something that can capture odours such as a carbon filter, air scrubbing or a nano-coating.
How Effective Are Air Purifiers?
We know what air purifiers can do but how effective are they really? Will they realistically make a difference to the air you breathe at home or at work?
The answer to this is complex. See the examples below. Fortunately, the basic mechanics used in air purification do work.
- A properly-manufactured HEPA filter will remove over 99% of particles with sizes of 0.3-microns and above and air ionisers will remove particles from the air. However, not all air purifiers are made with the same quality standards and their application in the field isn’t either. For example, a small air purifier in a large room, or a poorly manufactured purifier, may do very little to improve the overall quality of the air you’re breathing. On the contrary: it can produce the opposite effect, by giving a “false sense of security”.
- Purifiers that use HEPA filters, for example, can face issues when trying to filter larger particles than they’re designed for and if made with a material such as cellulose, they can harbour mould growth and contribute to the problem of bad indoor air quality. That is assuming you have a genuine HEPA filter. ‘HEPA-like’ filters are often not capable of delivering the same level of filtration and it’s not always clear which one you are buying. Currently, they all “look” the same.
- Ionisers are notoriously less-reliable than purifiers working through standard filtration and some research has found that small ionisers have very little effect on the air around you. Additionally, as they work by sticking particles to surfaces, they may simply be rearranging particles around your home, which could be dispersed again when someone opens a door, creating a draft, for example.
- Ozone air purifiers are not backed up by a strong body of research. For example, the Environmental Protection Agency found that only ozone generators that produced dangerous levels of ozone could truly purify the air.
The bottom line is that air purifiers can be very effective. A top-grade air filter placed in a machine capable of processing an adequate higher volume of air for your spaces will remove a high percentage of allergens and dust from the air around you. With a nano-coating, it can go further and destroy odours and viruses.
When working well, there is strong evidence that air purifiers can reduce the symptoms of allergy sufferers, decrease levels of particulate matter (PM2.5 and PM10) and with some varieties of purifiers, reduce the concentration of harmful gases and the transmission of viruses and bacteria.
How well it manages to do that will depend on the purifier machine itself and how you place it around the building.
Choosing an air purifier
When it comes to choosing an air purifier, the questions you need to ask are:
- What do I need an air purifier for?
- What is the space that I need to purify like?
- What are the compromises I’m willing to make?
With the first question, there are multiple possibilities. If you want to effectively target dust and allergens, then you will want a good-quality air filter. Pay attention to the materials used in a filter and buy from manufacturers who have proven the effectiveness of their product.
For odours, you will need some form of charcoal filter or nano-coating. This is also true for harmful gases such as some volatile organic compounds (VOCs) and carbon monoxide. Regular HEPA filters won’t cut it on their own.
When it comes to your space, you need to question what’s suitable. A small, low-power model, low-end desk purifier may be able to clean the air around you if you place it on your desk, but won’t do much if you want to clean the air in a large room. Importantly, an air purifier isn’t a substitute for stopping dirt, allergens, bacteria and gases from entering or accumulating in your home, and most of the air purifiers will require some level of maintenance to perform well for long periods of time.
When choosing a purifier, consider the following:
- Is it using proven air purification techniques such as filtration or ionisation?
- What material is the filter made of? Are you buying from a trusted manufacturer?
- Will it be noisy or have too many lights? If yes, how loud and how bright will the purifier be? Remember, you will still want to sleep while the room you are in is being cleaned.
- How often will I need to replace or clean the filter? Note that carbon filters can halve the lifespan of a filter.
- Will the purifier filter remove odours and harmful gases?
- Will the purifier filter remove bacteria, viruses and mould?
A good purifier will last for many years and can offer a considerable increase in quality of life, so make sure you do the research. We believe that our Smart Air purifier will deliver on all of these factors, offering an unparalleled air purification system.
Introducing Smart Air
At Smart Separations, we’ve designed what we think is one of the most powerful air purifiers on the market.
Smart Air uses a ceramic microfilter that is naturally antibacterial and anti-odour, anti-clogging and with careful maintenance, doesn’t need replacing, just washing. Our coating technology allows the purifiers to eliminate and destroy not just dust and allergens, but also odours, harmful gases, bacteria and viruses, including Coronaviruses. All of this without the need for ozone or UV.
If you’d like to find out more about Smart Air or the technology behind our ceramic microfilter and ViraTeq™, then message me today. Further announcements will follow.
