Air Purifier Buying Guide – How To Find The Right Air Purifier in Australia

Air Purifier Buying Guide – How To Find The Best Air Purifier



This is a comprehensive air purifier buying guide for Australians that will help you to find the best air purifier for your unique situation. The guide will explain what an air purifier is and why you might want to use one. It will also go into detail about the main filtration technologies and their suitability for various airborne pollutants. Additionally, we provide a step by step selection process that walks you through the most important things to consider when buying an air purifier.


Why Use an Air Purifier?

There are many forms of pollutants in the air that we cannot normally see, but just because they cannot be seen doesn’t mean that they are harmless. Air pollutants in your home may consist of things such as living microorganisms, chemical vapours and other microscopic particles that can trigger allergic reactions, affect normal breathing and compound the symptoms of chronic respiratory illnesses. A good quality air purifier with the right types of filter technology can remove most allergens and other air pollutants in our homes.

Obviously, the best strategy is to remove the source of pollutants from your home however; this is not always practical or even possible, so an air purifier or other form of filtration will be the best option.

Unfortunately, there is still some scepticism about air purifiers. The claims that Air Purifiers clean polluted air are not just some conjured up myth. Air Purifiers use tried and tested technologies along with new innovations to effectively clean air under many different conditions. Numerous tests have been performed and much data are available to support the claims. The main reason for the continued scepticism is from people buying cheap low-quality air purifiers that don’t perform to expectations. As with many other things quality does cost, so in most cases when buying air purifiers, you will get what you pay for.


What Actually Is an Air Purifier?

Put simply, an air purifier is a machine that is designed to remove airborne pollutants within an enclosed area. Most air purifiers use single or multiple fans to continuously cycle air through a series of filters that capture dust, pollen, pet dander and hair as well as gaseous pollutants, bacteria and other microscopic particulates. There are other types of air purifiers that don’t use a fan to cycle air through the unit however; most domestic air purifiers that you will come across will use a fan designed for continuous operation.


Two Main Categories of Domestic Air Purifiers

There are several technologies that air purifier manufacturers have available to them. Some air purifiers can have up to six different filtration technologies in a single machine however; the actual cleaning efficiency of each air purifier may vary widely. These efficiency variations are a result of factors such as the filter technologies used, filter size, filter quality, filtration sealing, air flow rates due to fan size and air flow design. 

Most air purifiers will fall into one of two categories; general purpose or specialised.

  • General purpose machines tend to use several different technologies together but may not be capable of handling some of the more extreme airborne pollutants such as higher toxicity chemical vapours and heavy odours.
  • Specialised machines such as the InovaAir Airclean E20 Chemical Plus will generally possess fewer technologies but use heavier duty, specially modified, higher quality and more expensive filter components to better target certain types of pollutants and remove them more efficiently.




Step 1 - Identify the Types of Pollutants That You Want To Target


The first thing to consider when buying an air purifier is what types of pollutants you actually want to target. If you suffer from a particular respiratory condition, then what types of allergens or pollutants trigger your symptoms. Do you have pets? Do you live in a dry dusty area? Do you live in the city or near a highway where vehicle pollution is a concern? Have you just moved into a new home with new paint, carpets and furniture that are off-gassing?

It is important that you identify exactly what pollutants are affecting you or what ones have the potential to. Once you know this, it will be easy to check each air purifiers specifications and features to identify the correct model for your situation.


Step 2 - Find the Right Filter Technologies


Now that you have identified the types of pollutants that need to be targeted, you can search for the most effective technologies for each type of pollutant.



The primary purpose of a pre-filter is to remove larger dust particles that are still suspended - Human hair - pet dander - lint etc. They can also remove specific pollutants If they are modified/infused with antimicrobial, carbon or oxidising agents.

All good air purifiers will have cleanable pre-filters to remove larger particles. A pre-filter will also help to extend the life and performance of the main filters within an air purifier.


HEPA Filters

Removes: Particles such as Mould Spores - Pollen - Dust - Pet Dander - Fine Pet Hair - Visible Smoke particle - Bacteria - Viruses - Dust Mites & Their Waste

Does Not Remove: Vapours or gases such as Chemical fumes - Cigarette odours - Organic & Animal Odours - Noxious gases - Vapour based Volatile Organic Compounds (VOC’s)

High Energy Particulate Arresting (HEPA) filters continue to be the foundation filtering technology for many air purifiers. There are some newer innovations available that don’t utilise HEPA technology however; most air purifiers will have HEPA filtration as their primary filter.

Beware! Not all HEPA filters are of the same quality and it is easy to be misguided by marketing hype.

You will come across many fancy names & technical terms used for HEPA filters which make them sound great but unfortunately; they wont deliver on quality or performance. For the highest effiency HEPA filters, look specifically for these terms “H13 HEPA”, "H14 HEPA" or “Medical Grade HEPA”. These are high efficiency and high-quality filters that can remove a minimum of 99.97% of particulates at 0.3 microns in size (0.3 micron is considered to be the most penetrating particle size for HEPA testing. This metric is used in US HEPA standards and is becoming a benchmark for HEPA based air purifiers around the world). Some manufacturers will also state the amount of surface area of their HEPA filters within their product specifications.


Activated Carbon Filters

Removes: Volatile Organic Compounds (VOCs) - Chemical Fumes - Gases - Cigarette Smoke Odour - Aerosol Vapours - Aldehydes - Light Cooking Odours

Does Not Remove: Pollens - Mould Spores - Dust Mite - Dander – Dust - Activated Carbon does not remove much more than the above gaseous elements and odours so it should be used in combination with other filter technologies such as True HEPA. Most air purifiers will have both HEPA & Activated Carbon as standard however; the quality and quantity of activated carbon will differ greatly between brands.

Activated Carbon is the most commonly used element in filters that target odours, volatile organic compounds, paint vapours, adhesive fumes, aldehydes and exhaust fumes. They work by way of a process called “adsorption” which removes particles that are ≤ 0.01 microns.

Once again, don’t be fooled by marketing hype.  High grade “Activated Carbon” is what you are looking for and the more of it the better. Normally, only the higher quality specialised purifiers will have substantial amounts of activated carbon and the manufacturers will usually state the amounts of activated carbon in either lbs or kg within the product specifications. In addition, some manufacturers may also combine the activated carbon with other oxidising compounds such as potassium iodide, activated alumina or potassium permanganate to optimise the removal of specific high toxicity pollutants like formaldehyde.

The InovaAir E20 Chemical Plus is one such specialised air purifier designed for heavy chemical vapours, formaldehyde and aldehydes. It has a 10kg activated carbon filter and offers an option of including a potassium permanganate filter specifically for formaldehyde & aldehydes.


General purpose air purifiers may also have activated carbon filters however; they will not have the same amounts of carbon that the top end specialised units have.

IMPORTANT! Do not use air purifiers with activated carbon or zeolite filters in damp rooms such as bathrooms, pool rooms and saunas as the excessive moisture in the air can ruin the filters very quickly! Manufacturers will easily recognise moisture damage and will not cover this with their warranty so if you are in a situation where there is excessive moisture, you should use a good quality dehumidifier to remove all moisture from the air before using an air purifier.


Negative Ion Generator (Negative Ionisers)

Removes: This technology will interact with particles as small as 0.1 microns – Dust – Pollens - Mould spores - Visible Smoke etc. however; these machines don’t really “remove” pollutants from the room. By emitting charged ions into the air, oppositely charged airborne particles attach forming clusters that become too heavy to stay suspended and simply fall onto the ground or attach to other charged surfaces such as furniture and walls.

The technology works but is not ideal when used on its own so many manufacturers are now using negative Ion generators in the final filtration stage as a facilitator to wellbeing. The negative ions are released into the air to re-balance, recharge and re-invigorate your indoor atmosphere, similar to natural occurrences of high negative ions such as near waterfalls, crashing waves or after a thunderstorm. Although some people may be sceptical about negative Ion generation, there have been many anecdotal reports of wellbeing from people who have used negative ion machines and air purifiers with negative ion features.

IIMPORTANT! Beware of cheap and nasty imports that can be bought directly from overseas websites – do not be tempted to buy ionisers, negative ion generators, electrostatic purifiers or oxidising machines as they may not meet Australian & International safety standards. The cheap design, materials and working parts used in some of these low-quality machines could potentially generate high amounts of ozone above prescribed safe levels for humans. (Definitely a no go for asthma sufferers)   


Electrostatic Filtration

Removes: Fine particles down to 0.1 microns - Dust - Pollen - Mould Spores - Visible Smoke

Does Not Remove: Odours - Gases - Vapours

Electrostatic machines are very quiet as there are no large fans or filters to create pressure drop noise from forced air. Electrostatic air purifiers take negatively charged ionisation a step further to actually remove the particulates from the room. They use electrostatic collection plates that are negatively charged to attract and collect the particles as they pass between the plates. Regular cleaning of the collection plates is a necessity and failure to keep them clean will result in electrical arcs between the collectors. Additionally, if they are not properly maintained, particulates will eventually fuse to the collection plate making it incredibly hard to clean off.


UV-C Filtration & Sanitisation (Photocatalytic Oxidisation - PCO)

Removes: Has the ability to destroy micro-organisms, viruses, bacteria, mould and VOCs. Helps to disinfect the air to prevent spread of illness.

Does Not Remove: Does not remove allergens such as dust, or larger solid airborne particulates so it is not ideal on its own and should be used in combination with HEPA & activated carbon filters.

Air Purifiers with a UV filter stage use the UV-C band of the ultra violet spectrum which is particularly effective on germs and viruses. This type of UV filtration uses broad spectrum ultraviolet light, that oxidizes volatile organic compounds and eliminates microorganisms collected by a catalyst surface. The most popular catalyst used is a Titanium Oxide TIO2 filter. Photocatalytic oxidation (PCO) is becoming a popular technology with several brands.

Check out the Airomaid range of air purifiers that use UV-C with a TiO2 catalyst filter to effectively destroy bacteria, viruses and VOCs.


Plasma Ion Generation (PlasmaWave & Plasmacluster)

Removes: Odours – Bacteria – Viruses - Other volatile organic compounds

Does Not Remove: Does not remove allergens such as dust, or larger solid airborne particulates so it is not ideal on its own and should be used in combination with HEPA & activated Carbon filters.

Plasma Ion generation is a harmless technology that breaks apart odours, chemical vapours, and pollutants at the molecular level. This technology works with naturally occurring water molecules in the air to create billions of short life Hydroxyl Radical's that separate hydrogen molecules from pollutants transforming them into clusters of harmless molecules.

Check out these Winix air purifiers that use the PlasmaWave technology to destroy odours, viruses, bacteria and various VOCs.


Silver Ion / Silver Nano

Removes: Bacteria – Viruses - Microbial Allergens - Bacterial Odours

Does Not Remove: Does not remove allergens such as dust, or larger solid airborne particulates so it is not ideal on its own and should be used in combination with other filter technologies.

Generally, more of an antimicrobial additive to pre-filters Silver Ion or Silver Nano filters are designed to kill airborne microbes, viruses and harmful bacteria. Silver ions are used in many different types of products for their antibacterial and antimicrobial properties. They work by combining with proteins of the microbe cell and cell walls. Once the microbe cellular structure has been compromised, their DNA and replicative functions are disrupted preventing any new cell production. This technology may come as an entirely separate filter or it can be incorporated within other filter technologies such as a HEPA. Some dehumidifiers have a Silver Nano pre-filter.



Ozone (O3) is a gas that consists of three oxygen atoms which makes it a powerful oxidiser. Do not use an ozone generator for any domestic purpose as the gas can be harmful to humans, especially in non-ventilated spaces where it can be trapped and concentrated further. Ozone generators are however; one of the most effective odour eliminators and are better suited to commercial and industrial applications. Even in commercial applications it is important that the treated area has been well ventilated and tested for safe O3 levels before allowing people to enter the area again.


Step 3 - Work Out Your Room Size (Coverage Area)


The next piece of the puzzle is to know the floor area size of the room that you want to use the air purifier in. If you have adjoining rooms open to each other you will need to know the combined floor area size. Most manufacturers will state a rated coverage area in square metres (m2) that the air purifier is capable of handling so all you need to do is match your room size with the specifications.

A good rule of thumb is to make sure that the air purifier can handle at least one third more area than what your room size is. 

Calculating your room area by multiplying the Length by the Width of the room.

Four to five air changes per hour is a good starting point for your air purifier to effectively maintain clean air, so be sure to carefully read the next step (Step 4).


Step 4 - Find Out the Air Purifiers' Clean Air Delivery Capacity


You will generally hear of two main terminologies when it comes to clean air delivery capacity; Air Changes Per Hour (ACH) and Clean Air Delivery Rate (CADR). Both are helpful metrics in determining the best air purifier for your needs however; there are some points to be aware of when using these which will be explained below.


ACH (Air Changes per Hour)

ACH is simply a measure of the number of times the total air volume of a room is circulated and cleaned by an air purifier within a sixty-minute period. Most manufacturers will provide the air delivery rate in cubic metres per hour (m3/h). This figure is then used to calculate the ACH as follows:

Air delivery rate in (m3/h) divided by the volume of the room (length x width x ceiling height)

Example: An air purifier delivers 360 m3/h and your room is 6m x 5m with a celling height of 2.4m

360 divided by (6 x 5 x 2.4) = 5 ACH

This means that the air purifier will be able to achieve 5 clean air changes per hour for that size room. Four (4) to five (5) ACH is a good starting point and anything higher is even better.

Limitations of the ACH

This number doesn’t give you any other quantitative or qualitatively measured figure to gauge cleaning efficiency, so it is important to know exactly what quality and types of filters the air purifier uses.

If you’re unsure, feel free to call us on 1300 174 659 and one of our knowledgeable staff will be happy to assist.


CADR (Clean Air Delivery Rate)

CADR is a standardised test set out by the Association of Home Appliance Manufacturers (AHAM). It is a voluntary (paid) verification program where manufacturers may submit their air cleaning products for testing under three specific pollutant conditions (tobacco smoke, dust and pollen).

How CADR is Determined

Each product is tested under the following conditions

The air purifier is placed into a testing chamber of 28.5 m3

The chamber is populated with the contaminants to a specific particulate level

The air purifier is run on its highest setting for a period of twenty minutes with particulate levels being continually monitored and recorded every two minutes.

The reduction in contaminants is then calculated against the initial levels and their natural rate of decay

This gives a quantitative and qualitative result for an air purifiers’ capacity to clean the air of these three contaminants, which is very useful information to the consumer.

A higher rating indicates that the unit will filter the air faster for that pollutant than a unit with a lower rating.

Limitations of CADR

The metrics that CADR represents may have the potential to lull consumers into a false sense of security. It is therefore important that consumers remember that these tests are only related to three of the many types of pollutants that we could be exposed to and that the tested particle size falls within a limited range.

Some points to keep in mind when looking at the CADR ratings

  • It is a voluntary verification program so not every brand will use these ratings therefore; you may not be able to compare some brands using this system.
  • It is also important to note that some of the most well-respected air purifier brands who manufacture top end machines do not use the CADR rating system. This does not mean that their products are inferior in any way.
  • CADR numbers are not able to indicate an air purifier's ability to filter out very small particles which are potentially, the most dangerous air pollutants. Even if an air purifier rates well in CADR it may be incapable of efficiently removing sub 0.1 micron sized particles.
  • Testing does not measure an air purifier's ability to remove gaseous pollutants such as volatile organic compounds, fumes, chemical allergens and other toxic vapours. If a consumer wants to target those types of air pollutants, they need to look beyond a CADR rating.
  • There is no indication or measurement of an air purifiers effectiveness over time. As the test is only twenty minutes in duration, it cannot determine an air purifiers consistency of effectiveness over extended periods.
  • CADR testing runs the air purifier on its highest speed setting so it does not account for cases where consumers will use the machine on lower speeds such as in the bedroom when they are sleeping.

The above is merely a recommendation of things to consider when using CADR. Both ACH and CADR provide very useful information but due to their limitations they should not be solely relied upon when choosing an air purifier.


Step 5 - Consider Noise Levels


Noise levels are also important to consider especially if you plan to use the air purifier in the bedroom. Most air purifiers can be noticeably audible at their highest settings so take note of the dB figure within the product specifications.

Remember, if you are using CADR as part of your selection process, that these ratings are determined when the machine is running at its highest speed. This is also most likely its noisiest output level.


Step 6 - Energy Consumption & Running Costs


Most manufacturers will provide the power rating in watts (W) within the product specifications. This figure represents the rate at which the device consumes energy and can be compared to other household appliances to get a true idea of how much electricity your air purifier consumes over time. Many air purifiers consume less energy than standard pedestal fans.

Good quality air purifiers won’t have any problem being run 24/7. When they are used this way, they generally only need to run on their lowest speeds most of the time unless there is a spike in pollutant levels.

Here is a hypothetical example of what an 80W air purifier might cost to run 24/7

Air Purifier Power Rating: 80W (Uses 80W on highest speed) 
Cost of Electricity ($/kWh): $0.25 / kWh
Running Time (hrs/day): 24

Cost per day approx: $0.48 (48 cents)            
Cost per month: approx. $14.50

In reality, this cost should actually be cheaper as you wouldn't normally be running your air purifier on it's highest speed 24/7


Step 7 - Filter Costs & Replacement Frequency


Another important thing to consider is the ongoing filter replacement costs. To calculate the ongoing costs, you will need to know the price of new filters and how often they need to be replaced. Some brands use lighter grade and less expensive filters that require frequent changes and other brands will use higher quality heavier grade filters that are more expensive but don’t require frequent replacement.

If you have heavier than average pollutant levels or are experiencing more frequent and severe symptoms due to higher levels of allergens and irritants, you may be better off choosing an air purifier with larger size and heavier grade filters. They will cost more up front, but should last considerably longer and perform much more efficiently for longer.


Step 8 - Warranty


Take note of a products’ warranty period and its terms as both the terms and length of coverage vary greatly between brands. Many household appliance warranties in general, can be extremely complex and confusing to consumers with the return procedures being totally overwhelming. If you purchase through us, we become your first point of contact so there is no need to attempt to deal with a manufacturer all by yourself.


Putting it All Together


After reading through this guide, you should now have a much better chance of finding an air purifier that is suited to your situation.

As there are so many different brands, models and filter technologies out there in addition to a lot of smoke and mirrors marketing, it’s very easy to end up with something that is either just plain rubbish, has incorrect filter technology for your needs or just not powerful enough to cope with the room size.

We try to include a wide range of products in our store catalogue that cover various concerns, applications and price points so you should be able to find the ideal air purifier. If you can’t find it, give us a call on 1300 174 659 and we will be happy to assist you.




You Still Need to Do Your Daily Cleaning

One misconception some people have is that when they buy an air purifier it relinquishes them from all other regular cleaning chores. This is not the mentality to have as an air purifier is not a vacuum cleaner or dust extractor.

    Most of the dust and grime that accumulates on floors, walls and furnishings are visible to the eye therefore; they may also be too heavy for an air purifier to capture and filter out so conventional cleaning is still necessary.

    It’s always a good idea to have your air purifier running on high speed when carrying out cleaning chores such as dusting and vacuuming to capture anything that has been disturbed and broken down to become airborne.


    Buy from Australian Retailers

    Don’t buy air purifiers from overseas wholesale or auction websites. Even when the website is Australian, some allow overseas sellers to sell directly into Australia.

    We have had several people call us asking all sorts of questions on how they can rectify problems with their air purifier that they bought through one of these types of websites. The list of problems seem to be endless, but here are some more common one's that we hear about:

    • incorrect power plugs
    • wrong voltage/power
    • cheap and flimsy construction
    • falsified & non certified specifications
    • counterfeit products & designs
    • product arrived damaged
    • extremely long delivery times
    • Australian Customs importation issues
    • safety concerns and no safety certifications
    • warranty not valid in Australia
    • Australian repairers won’t touch overseas products



    This guide should provide you with enough information to make a well-informed purchase through our store however; if you require some help or need further questions answered please contact us and one of our team members will be happy to assist. CALL US ON: 1300 174 659 




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    Air Purifier Buying Guide – How To Find The Right Air Purifier in Australia last updated 5/1/22 09:50




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