How we test air purifiers at Ideal Home

We've put multiple air purifiers through Ideal Home's testing process to find the best-in-class. Here's how we do it.

Five air purifiers of various sizes lined up on a tiled floor in a room with a pale yellow wall
(Image credit: Future / Amy Lockwood)
Amy Lockwood
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At Ideal Home, we're always at the forefront of the latest home and garden product launches. But, before we recommend any products to our readers, we want to make sure each product does what it claims and to see how well it measures up against the competition.

That's why we put every product we can through Ideal Home's testing process.

When it comes to air purifiers, we follow exactly the same review formula. We task our product experts with putting each air purifier through its paces to test out how easy it is to use, how well it does its job, and if it offers good value for money. Only our top recommendations are then included in our guide to the best air purifiers you can buy.

On this page, we'll explain exactly what tests each air purifier is put through before we decide on its review score. Only the very best air purifiers are given full marks and Ideal Home's coveted five-star review rating. 

If a product doesn't achieve at least four out of five stars, then it won't have an Ideal Home Approved badge, and likely won't be included in our guide to the best-in-class. The only exception to this rule might be if a product offers a unique feature that can't be found elsewhere, or if it offers a particularly budget-friendly price tag.

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)

How we test air purifiers at Ideal Home

Whilst most air purifiers' technical specifications – such as CADR (clean air delivery rate) and HEPA filtration performance – are based on the air purifier's performance in a sealed laboratory, at Ideal Home we prefer to test out each air purifier within a home environment. This means we can assess each air purifier's performance in real-life conditions.

Our first test involves testing each air purifier's ability to detect and filter out smoke. 

If the air purifier features a built-in air quality sensor then we switch the air purifier into automatic mode, light a match a safe distance from the air purifier, allow the match to burn out, and then time how long the air purifier takes to register the drop in air quality. 

We then time how long it takes each air purifier to filter the smoke particles from the air and return the air quality to a 'very good' level of below 10µg/m³ PM2.5. We also do a 'nose test' to see if someone entering the room after the air purifier has 'done its thing' can still smell any trace of smoke.

If the air purifier doesn't feature an automatic mode, then we only perform the latter part of the test, and we use an independent device to measure how long the air purifier needs to run before the air quality is improved.

A lit match and a candle in front of a white air purifier

(Image credit: Future / Amy Lockwood)

We also perform a similar test by spraying aerosol deodorant into the air near the air purifier, and timing how long each air purifier takes to register and then filter out any VOCs (Volatility Organic Compounds) and odours that may be present.

So far in these tests, our Philips 3000i Series AC3033/30 Connected Air Purifier review and Blueair Blue Max 3250i air purifier review have delivered the best results. The larger (and more expensive) Philips 3000i Series registered the quickest response and results times, taking just three to five seconds to register the dip in air quality, and around thirty seconds to return the air quality to below 10µg/m³ PM2.5 in these two tests.

An aerosol deodrant with the cap off on a wooden table in front of a grey Blueair air purifier

(Image credit: Future / Amy Lockwood)

We also put each air purifier's odour-filtering capabilities to the test in the kitchen. 

Our standard test involves closing the kitchen windows and doors, leaving any extractor fans switched off, and frying up two rashers of plant-based bacon until it's nice and crispy. 

We then time how long each air purifier takes to register the decrease in air quality caused by the bacon fumes, and how long each air purifier takes to remove the cooking fumes from the kitchen.

This is the test that usually sends each air purifier into overdrive, with most of those appliances that feature a built-in air quality sensor registering a deterioration to 'very poor' air quality as soon as the bacon starts frying. 

The Philips 3000i Series, Blueair Blue Max 3250i, and AEG AX91-604GY Connected air purifier were all largely neck-and-neck in this test, all averaging eleven minutes to bring air quality back into the 'good' zone. And the Levoit Core 300S air purifier wasn't that far behind at fifteen minutes.

A frying pan holding two rashers of plant-based bacon on a stainless steel gas hob

(Image credit: Future / Amy Lockwood)

We also put each air purifier through a dust test. This glamourously involves emptying the contents of a vacuum cleaner next to the air purifier to see if it triggers a response from those air purifiers that feature a built-in air quality sensor.

The AEG AX91-604GY Connected Air Purifier on a tiled floor with a pile of dust and a Dyson vacuum cleaner next to it

(Image credit: Future / Amy Lockwood)

We then compare the results of these tests to rate each air purifier's overall performance. 

However, performance isn't the only thing we measure when arriving at a final score for each air purifier and awarding it an Ideal Home rating.

We also take into account how easy each air purifier is to assemble and set up on its arrival, its overall design and any stand-out design features, how easy it is to use, and how accessible its controls are. We also assess each air purifier's noise levels during operation and its portability in case it's important to the purchaser that they can easily move the air purifier from room to room. 

In arriving at a final rating, we also weigh up each air purifier's cost, and if it offers good value for money for its intended purpose. After all, most of us would appreciate that a more powerful air purifier capable of filtering the air in a large space up to 150m² is likely to cost more than a small air purifier designed for spaces up to 20m².

In addition, we factor in ongoing costs, like energy efficiency, which will impact how much an air purifier costs to run, and the cost of replacement air filters.

Five air purifiers of various sizes lined up on a tiled floor in a room with a pale yellow wall

(Image credit: Future / Amy Lockwood)

Our air purifier reviews

Looking for a review of a particular air purifier? You'll find our top recommendations in our round-up of the best air purifiers. However, we've tested far more air purifiers than are contained in our shortlist. If you're searching for a review of a particular model, you may find it below.

Our Consumer Experts

Our Consumer Experts are members of the team who have gained specialist knowledge of certain product categories. 

Earning a Consumer Expert certification involves researching a specific product category, and gaining hands-on, practical experience with a variety of products within that category by way of testing, reviewing, and keeping up to date with the latest product developments in that field. We break this down into five sections.

1. Testing 
Our Consumer Experts have hands-on experience testing the bestselling and best-performing products on the market. This then becomes the benchmark against which all other products in this category are reviewed and rated.

2. Product research 
Our experts immerse themselves in each product category, learning everything there is to know about the product, from how it's made, to its biggest pros and cons. 

3. Behind the scenes 
As well as hands-on product testing in a home environment, our Consumer Experts have also gained insider knowledge on the products they test. This might be through factory visits, showroom tours, or comparison testing days at our testing facility.

4. Industry knowledge 
Our experts know the nitty-gritty of each product category. They regularly speak with industry experts such as product developers and retailers, they know the market leaders and the growing trends within the industry. They are non-biased and able to formulate an honest judgement about the unique selling points offered by different products on the market.

5. Wider opinions 
Our experts don't just rely on their own knowledge, they also seek input from the wider team and carefully research customer product reviews to gauge wider product satisfaction, noting and investigating any regularly occurring customer feedback.

Below, you can see which members of the team are certified Consumer Experts when it comes to testing air purifiers

amy lockwood
Amy Lockwood

I'm Amy, Ideal Home's air quality expert. Along with research into how air purifiers work and what makes an air purifier worth investing in, I've also now tested out multiple air purifiers to see how well they perform in a variety of air quality tests, including bestselling models from Philips, AEG, Blueair, and more.

Amy Lockwood
Amy Lockwood
Sleep Editor

Amy is Ideal Home’s Sleep Editor and the Ideal Home Certified Expert on Sleep. She's spent the last four years researching and writing about what makes for the best night’s sleep during the day and testing out sleep products to find the best-in-class by night. So far she’s clocked up over 10,000 hours of pillow, duvet, and mattress testing experience.

Our go-to for all things sleep-related, she’s slept on and under bestselling products from Simba, Emma, Hypnos, Tempur, Silentnight, Panda, and many many more.

As a hot sleeper, Amy is always on the lookout for the most breathable bedding, but she also leads a wider team of testers to ensure our product testing encompasses both hot sleepers, cold sleepers, front sleepers, back sleepers, side sleepers, and everything in-between.

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