Which type of air purifier is best for you? Experts explain the key differences between the most popular filtration methods

Air purifiers, demystified

A selection of five air purifiers of various sizes on a wooden table in a room with pale green walls and indoor plants on shelves
(Image credit: Future / Amy Lockwood)

Knowing which type of air purifier is best for you before purchasing one will ensure that the investment you make is one that you'll be pleased with for years down the line.

Among the roster of best air purifiers currently on the market, there are a handful of things that differentiate them from one another that go beyond just size and noise levels.

While air purifiers all generally work to achieve the same result of improving indoor quality, certain types of air purifiers work best in specific situations and for addressing certain issues. For example, certain air purifiers help with allergies better whilst some air purifiers are geared to help deodorise damp, musty smells in the home.

To help you determine which type of air purifier is best for you, we've asked experts to distinguish the key differences between the most popular kinds of air purifiers and what you can expect from each type.

Which type of air purifier is best for you?

'Air purifiers are great for people with asthma, allergies, and pets, as they help remove harmful impurities from the air. However, with so many options available, it can be overwhelming to choose the right one,' notes Joshua Warren, air treatment expert at AO.com.

'There are a few things to consider when choosing an air purifier as picking the correct filter for your surroundings can impact how effectively it works within your home,' adds Marc Duckworth at Russell Hobbs.

Before deciding to invest in a certain model, here are the basics you ought to be clued up on regarding the top 3 most popular types of air purifiers available and how to figure out if they will target the irritant you're trying to deal with.

The Philips 3000i Series AC3033/30 Connected Air Purifier in a bedroom with a wooden bed and blue walls

(Image credit: Philips)

1. HEPA purifiers

HEPA purifiers are often noted as the gold standard in air purifiers, standing as the best option if you're looking to invest in an air purifier to help with hay fever.

This is because 'HEPA purifiers have an incredibly effective filter made up of thousands of extremely fine fibres and can catch the tiniest of particles, with a 99.97% efficiency in trapping particles, allergens, and pollutants,' explains Joshua.

Given this, going for a model with a HEPA filter is a no-brainer for people who suffer from respiratory issues and want a reliable way to reduce allergens in the home and stop dust via the addition of an air purifier in their space.

Most of the top-rated air purifiers we've tested use HEPA filters such as the Blueair Blue Max 3250i which we gave a glowing 5 stars in our review – so we can attest to HEPA purifiers being a top choice.

In addition, Trevor Brewer, managing director at Solenco UK adds that a HEPA filter also catches bacteria and viruses, making this choice especially useful in protecting children. This could be something to consider if you're in a family household.

These are three of our favourite air purifiers that use a HEPA filter.

2. Ionizer purifiers

Unlike HEPA filters which simply capture dust, allergens, and pet dander, ionizer purifiers work a little differently to rid your target room of these airborne particles.

'Some air purifiers also include ionic filters in the form of ionizers, which release negatively charged ions into the room to attach to positively charged particles like dust, bacteria, and pollen, making them heavier and easier for the air purifier to capture,' explains Colin Swift, product manager at AEG. This, in turn, makes an ionizer purifier a great option for those seeking a more comprehensive cleaning of their space.

However, ionizers are not without their warnings. Although they are a more low-maintenance option in the grand scheme of air purifiers, some ionic air purifiers can emit harmful byproducts that can pose a risk to those with respiratory issues.

'Ionic purifiers produce ozone which can be dangerous if consumed in high levels,' warns Marc. Instead, it's generally advised to ensure the air purifier you want to purchase has 3-layer filtration, as these are completely safe to use in the home and are incredibly effective.

The AEG AX91-604GY Connected Air Purifier being tested in a room with green walls and a wooden table

(Image credit: Future / Amy Lockwood)

3. Active carbon filter purifiers

Alternatively, if you're looking to invest in an air purifier for the sake of wanting to deodorise bad odours in your home, it could be worth considering a model with an active carbon filter.

'Active carbon filter purifiers use activated carbon to absorb gases and odours, including volatile organic compounds (VOCs) from household products and smoke,' explains Joshua. 'These are best for homes with smokers, pets, or those concerned about eliminating odours and harmful gases.'

However, Chris Michael, managing director of Meaco does preface that 'there are not many of these about as most manufacturers pay lip service to carbon filters,' adding that to effectively get rid of smells and VOCs, you need a good weight of carbon.

Luckily, Colin notes that filtration methods can be combined, meaning that some of the best air purifiers can successfully tackle both capturing particles and deodorising smells without falling short in either category.

This concept holds up in the AEG AX91-604GY Connected Air Purifier, which we've rated as the best choice for larger spaces in our review with active carbon and ionisation to combat those problem areas in the home.

Tips for choosing the best air purifier for you

Once you've figured out which kind of air purifier feels best suited to you – choosing between HEPA, ionizer, and active carbon filters – you've got to ensure you nail the sizing if you want it to work its best inside your home.

To find out the right size, measure the room in all three dimensions to give you the cubic air volume and go from there. As a general rule of thumb, Chris advises:

  • 3x an hour for minor problems
  • 5x an hour for problems that effect your health
  • 7-8x an hour for issues that see you have regular medical support/hospital visits (in these cases, talk to your doctor as well)

'The clean air delivery rate (CADR) is also a handy measurement that recognises the speed an air purifier can clean a certain volume of air,' adds Marc. 'The higher the CADR, the larger the room the purifier is suitable for, but a super high CADR in a small room is unnecessary.'

Of course, there are also other things you can consider when looking at different kinds of air purifiers such as noise levels, energy efficiency, and additional smart features like Wi-Fi connectivity and sleep timers. But, these are beside the point right now as we're mainly focused on the type of filtration best suited for your needs.

When you've decided which type of air purifier is best for you, then you can start to streamline your search more specifically to hit all the non-negotiable features you're seeking out in this home appliance.


Do air purifiers use a lot of electricity?

Considering air purifiers often need to be switched on for long periods to work effectively, it's natural to be worried about the cost of running an air purifier.

Thankfully, you'll be happy to know that air purifiers are actually on the relatively cheaper side to run in comparison to other air treatment appliances. But of course, this all depends on the size of the room and the size of your air purifier – so costs can still add up.

Therefore, it may well be worth looking into air purifiers that are more energy-efficient to help you save energy at home.

What is the best method of air purifier?

Generally speaking, many experts would agree that HEPA filtration is the most effective and safest method for purifying and improving indoor air quality. However, the choice still lies with you on which air purifier you deem best for your specific needs and situation.

Having read the above advice, we hope you feel better placed to decide which type of air purifier is best for you, so you can confidently make the investment with no regrets.

Jullia Joson
Junior Writer

Jullia Joson is a Junior Writer at Ideal Home. She's always loved all things homes and interiors, graduating with a bachelor's degree in Architectural Studies from the University of Nottingham where her love for journalism blossomed following her internship at ArchDaily. Now focused on home tech, Jullia works on writing features and explainers to help people make the most of their home appliance investments. When she isn't writing, she loves exploring the city, coffee shop hopping, and losing hours to a cosy game.