AEG AX91-604GY Connected Air Purifier review – 'the best we've tested for an open-plan home'

Our AEG AX91-604GY Connected Air Purifier review puts the brand's highest-specced air purifier through its paces to see how it compares to the best air purifiers the Ideal Home team has tested.

The AX91-604GY is designed for use in large spaces, with the brand stating it can filter the air in a room measuring up to 129m2. It does this by way of a 5-stage purification process that utilises a pre-filter, an antibacterial layer, a pre-charged True EPA12 filter, an active carbon filter and an optional ionisation function.

The AX91-604GY has a very impressive clean air delivery rate of 620m3/h (that's CADR for short, a measurement which describes the volume of clean air an air purifier produces per minute) which is nearly three times that of smaller air purifiers we've tested. However, the AX91-604GY also has an impressive price tag to match. 

So is the AEG AX91-604GY Connected Air Purifier worth the investment? Having put it through its paces in my open-plan living/dining room, I certainly think it's a great air purifier for use in large rooms and open-plan spaces. Read on to find out why.

AEG AX91-604GY Connected Air Purifier review 

Specifications

• Recommended room size: 129m2
• CADR: 620m3/h
• Noise levels: 17-32dB
• Filter type: 5-Stage Pre-filter, Antibacterial Layer, Pre-charged True EPA12 Filter, Active Carbon, and Ionization
• Dimensions: H72.5 x W31.5 x D31.5 cm
• Weight: 8.9kg
• Wattage: 4-41W
• Smart App connectivity: Yes
• Timer: No
• Auto mode: Yes
  

How I tested

Amy Lockwood

I'm Amy, one of the Ideal Home team's Ecommerce Editors. My job involves putting all manner of products through their paces to find the best recommendations for our readers. I've tested multiple products that promise to improve the air quality in our homes and deliver indoor climate control, including the best dehumidifiers, best fans and best portable air conditioners on the market. I tested the AEG AX91-604GY Connected Air Purifier in my own home to see how it coped with everyday decreases in air quality caused by smoke, VOCs, cooking fumes, and dust.

Assembly and set up

There's very little assembly needed with the AEG AX91-604GY Connected Air Purifier. Once it's unboxed you simply need to pull out the air intake door at the back of the purifier so that you can remove the protective plastic packaging from around the air filter. 

This is made easy thanks to a fabric handle that you pull outwards to remove the door. Magnets then help to hold the door in place when you reposition it onto the purifier afterwards.

Beyond that, all the set-up you need to do is download the AEG Wellbeing App if you want to make the most of the air purifier's Smart features or connect it to Google Home if you want to integrate it into the rest of your home's Smart tech. 

However, the AX91-604GY can also be operated via the onboard controls on the top of the unit with only a little sacrifice of functionality. 

One of the few functions that can only be operated via the App is the ionisation function. AEG states that this optional ioniser function 'produces negatively charged particles (negative ions) using electricity' which the AX91-604GY then 'pushes out into the room to attach themselves to oppositely charged particles in the air – such as dust, bacteria, viruses, pollen, smoke, or other allergens – making them bigger, heavier particles that either attach themselves to surfaces including the ground or are captured by the filters of the air purifier on the subsequent run(s), thereby eliminating them from airborne circulation'.

If you want this feature turned on you just need to toggle the setting in the AEG Wellbeing App.
 

Design

The AEG AX91-604GY Connected Air Purifier is a stylish device, which is good news because its H72.5 x W31.5 x D31.5cm measurements mean it's going to become a bit of a focal point in any room you use it in.

Its height means that this is an air purifier that's better sat on the floor rather than a surface, but considering its overall size, its 31.5cm diameter footprint isn't too space-hungry.

And, from the moment you unbox it, the AEG AX91-604GY Connected Air Purifier feels like a quality appliance. As I've come to expect from the German-founded brand after previously testing a few other products, there are some nice design touches that instantly make AEG's AX91-604GY feel like a premium product.

The lower half of the AX91-604GY houses the air filter, which is protected by hexagonal honeycombed metal that's finished in matt grey – none of the plastic bodywork that's common with cheaper air purifiers – and the upper half is finished in a tonal grey fabric.

The metal grill and the fabric upper both help to soften the appearance of the AX91-604GY so it feels far more like a considered piece of furniture than an unsightly appliance plonked in the middle of a room, and the tonal shades of grey cleverly help its relatively large form not to feel as bulky as it otherwise might.

The robust leather (or leather-look, I couldn't find material details listed) carry handles on either side of the appliance are also a nice touch that adds to the AX91-604GY's minimal yet luxe styling.

And then there's that distinctive hexagonal air outlet at the top of the air purifier that makes the AX91-604GY stand out from the crowd. 

Bang in the centre of this is the touch-sensitive digital control panel which offers by far the most intuitive and user-friendly interface of any air purifier I've tested so far.

The control panel features an on/off button and a Mode button that allows you to toggle between Manual or Smart mode. 

The Manual setting allows you to manually adjust the fan speed, which you do by swiping your finger over the illuminated arc that's displayed on the control panel. The more of the arc that's lit up, the higher the fan speed. In Smart mode, the air purifier uses the readings of the built-in air quality sensor to choose the appropriate fan speed automatically.

In both of these modes, the underneath of the hexagonal control panel lights up in one of six colourways to communicate the current air quality. There's green to indicate 'very good' air quality of 0-12 PM2.5, yellow indicating 'good' and a range of 13-35 PM2.5, orange for a 'poor' reading of 36-55 PM2.5, red for 'very poor' 56-150 PM2.5, purple for 'bad' 151-250 PM2.5, and maroon for a 'very bad' air quality reading of over 250 PM2.5.

Using the AEG Wellbeing App also gives you more detailed air quality data, and allows you to continue to monitor your home's air quality when you're out of the house.

Performance

Having been well and truly wooed by the AX91-604GY's digital LED display panel, I was eager to put the purifier to use to see how its clever controls worked in practice.

The AX91-604GY's Smart mode is a great feature that means you can save on energy by only using the fan speed necessary to clean the air, and this is the mode I put the air purifier into to perform the first test.

I was happy to see that when I first turned the air purifier on it displayed the green indicator light, communicating that the indoor air quality was currently in the 'very good' range.

To test out if it could pick up on changes to the air quality, I lit a match close to the air purifier and let it burn out to create smoke in the air. 

In Smart mode it took the AEG AX91-604GY Connected Air Purifier around 30 seconds to register the smoke particles and for the air quality indicator light on the top of the display to change from green to red. That meant the purifier had registered a drop to 'very poor' air quality so the appliance automatically increased the fan speed to return air quality to 'very good'. 

All in all, it took 4 minutes 28 seconds for the AX91-604GY to clear the air and return to standby mode, shifting through orange (poor), yellow (good) and then back to green (very good) air quality. I left the room and then re-entered to see if my nose agreed with what the AX91-604GY was registering and I couldn't smell any trace of smoke at all when I returned. Impressive stuff, and one of the best results from all the air purifiers I've so far put through the smoke test.

When I tested spraying aerosol deodorant in the vicinity of the air purifier the results weren't quite as positive. It took around 30 seconds again for the AX91-604GY to register the VOCs present in the deodorant, and although the fans did ramp up a gear, they only ran for 48 seconds before the AX91-604GY returned to standby. I tried the test again but got very similar results, which meant there was still quite a strong smell of deodorant left in the air.

I also tested the AEG AX91-604GY Connected Air Purifier in the kitchen to see how it coped with cooking fumes. My kitchen has a very old extractor fan that struggles to adequately remove cooking fumes, so I was interested to see how the air purifier would perform in comparison. 

To test out its powers I shut the kitchen door, made sure the windows were closed, left the extractor fan off and started frying two rashers of plant-based bacon whilst the AEG AX91-604GY Connected Air Purifier was running in Smart mode and positioned a safe distance away.

From when the bacon first started sizzling, it took the AEG AX91-604GY Connected Air Purifier 3 minutes and 48 seconds to register the cooking fumes, at which point the air quality indicator shifted through the colour spectrum to maroon, and the fan speed increased in line with the fumes intensifying.

By the time the AEG AX91-604GY swung into action the bacon had just about finished crisping up, so I snuck out of the kitchen, shut the door again, and set to work eating my bacon sandwich. All in all, it took 11 minutes and 48 seconds for the AX91-604GY to finish doing its thing, register the air quality as back to 'very good', and return to its lowest standby fan speed setting.

At this point, I re-entered the kitchen to see if my nose agreed with the AX91-604GY, and although there was still a faint smell of bacon, it was far less noticeable than it would have been had I been reliant on my not-very-efficient extractor hood or an open window during the frying process.

Lastly, there was the dust test to perform. Whilst the AX91-604GY was in Smart mode I emptied the contents of my vacuum cleaner onto the floor next to it. The air quality indicator remained a constant green for 'very good' air quality throughout this process – a bit of a surprise as I was expecting it to immediately register the dust particles floating around in the air before and after the dust settled as impurities and swung into action.

When I manually set the air purifier to its highest fan speed and performed the same exercise, I could see the dust particles being drawn into the air purifier's filter, but again the indicator light didn't show a decrease in air quality.

Seeing as the AEG AX91-604GY draws in air from 360°, it may be that the bulk of the air it was filtering was non-dusty and therefore overall the air quality remained high throughout the exercise. However, on higher fan speeds the dust was visibly being drawn into the purifier, which I guess is what counts! 

And, when the ioniser function was turned on via the Smart App, it may be that airborne dust particles were made heavier and sank to the ground, as AEG states will occur.

All in all a slightly mixed set of results, with the AEG AX91-604GY not quite as quick to react in the deodorant and cooking tests as the super-responsive Blueair Blue Max 3250i air purifier that I've previously reviewed, but producing very impressive results in the smoke test. Although in all tests the AX91-604GY certainly improved air quality considerably.

However, what was very clear from my testing was how well the AEG AX91-604GY could perform in a large space. I have an open-plan living and dining room, and smaller air purifiers I've tested, like the Blueair Blue Max 3250i and Levoit Core 300S air purifier, have struggled to filter the air in this larger space. However, the more powerful AX91-604GY took it all in its stride. 

That's perhaps no surprise as the AX91-604GY is specifically designed for use in rooms up to 129m2, and its 620m3/h CADR is nearly three times higher than that of the Blueair Blue Max 3250i and Levoit Core 300S.

To filter the air in a larger space, the AX91-604GY features what the brand dubs an 'AirSurround system', saying this 'creates a powerful yet smooth spiral movement of the indoor air that efficiently circulates and cleans the air'. And it certainly seems to work. 

In contrast to the smaller air purifiers I've tested, I could feel the air gently moving quite some distance from the AX91-604GY, with the powerful fan and spiral air outlets at the top of the air purifier ensuring the air circulated to all four corners of the largest room in my house.

Ease of use

The AEG AX91-604GY Connected Air Purifier is very easy to use, offering a touch-sensitive display that's responsive in all the right ways and a pleasure to use. 

It's also super simple to operate and gets full marks from me for user-friendly design. In fact, this is the most user-friendly air purifier I've tested in terms of ease of use.

The Manual swipe feature is especially fun to operate, so it's perhaps wise that the air purifier also comes with a Child Lock function you can activate either via the App or by long pressing the On/Off and Mode buttons simultaneously to ensure no one gets swipe-happy!

Noise levels

The AEG AX91-604GY Connected Air Purifier's noise rating is pretty low, officially measuring between 17-32dB, dependent on which fan speed it's operating in.

Like every air purifier I've tested, the AX91-604GY is still pretty loud on its most powerful fan setting, although it's not an unpleasant noise, just the sound of gushing air. However, hopefully, it's not that often you'll need the air purifier running on maximum, especially if you have it operating on Smart mode, whereby it kicks into the highest gear should air quality drop, but will remain on the far quieter low and medium fan speeds for the majority of the time. 

The great thing about the AX91-604GY's Manual mode is that the fan speed arc offers a lot of versatility in fan speed choice. Whereas most air purifiers only offer three-speed settings, the AX91-604GY delivers a far wider breadth of speed options so you can tweak its operation to whatever noise level you feel most comfortable with.

The only thing the AX91-604GY seems to lack that its competitors provide is a dedicated Night mode. On alternative models, the Night mode drops the fan speed of the air purifier to below its normal lowest fan speed setting whilst Night mode is activated. The AX91-604GY doesn't seem to offer this functionality specifically, but as mentioned above, the Manual fan speed arc allows much more control over the fan speed you choose anyway, so it's easy enough to create your own 'Night mode' and set the AX91-604GY to its lowest fan speed at bedtime so it doesn't disturb your sleep. 

I'm a light sleeper, but I found the white noise of the AX91-604GY easy to ignore when left running in the bedroom overnight.

Portability

A lot of consideration has clearly gone into its design to make the AX91-604G feel a lot less bulky than it might otherwise do, but, there's no denying it is still a relatively large, heavy, and cumbersome device. 

Measuring H72.5 x W31.5 x D31.5cm with a weight of 8.9kg, whilst this air purifier is portable, I certainly didn't find it was a model I wanted to move that often. 

When you do come to transport it from one room to another, the leather-look carry handles work well. But I still found its height made it a bit of a struggle to manoeuvring the appliance up or down the stairs. Unlike more compact designs, I couldn't envisage regularly moving this purifier from the kitchen to the bedroom in a two-storey home.

However, if you want to improve the air quality in a large room or an open plan home, then the AEG AX91-604GY Connected Air Purifier is a great choice. In this scenario, you can just leave the air purifier in situ and let the cleverly designed spiral 'AirSurround system' on the top of the unit, and the AX91-604GY's powerful fan motor, bounce air around the room to ensure filtered air reaches all four corners of your interior.

Energy use

The AEG AX91-604GY Connected Air Purifier uses between 4-41W of energy depending on which fan speed the appliance is operating in.

Whilst that's not as energy efficient as smaller air purifiers that average around 25W, it is still fairly low considering the air purifier's size and power. 

The AX91-604GY's Smart mode is also a great energy-saving feature. The fact that you can use the built-in air quality sensor to automatically control the air purifier's performance means that you're never wasting more energy than you need to maintain good air quality.

You can find out more about how much it costs to run an air purifier in our dedicated guide.

Filter replacement

The downside of pretty much every air purifier is that beyond the initial purchase price of the purifier itself, you also need to factor in the ongoing cost of replacing the air filter every so often. 

Generally, manufacturers advise that an air filter should be replaced roughly every six months as it will gradually become clogged up with particulate and its efficiency therefore reduced. 

AEG doesn't give specific guidelines for how often the AX91-604GY filter should be changed, but there's a warning light that illuminates when this is necessary. You can also track the filter's usage in the AEG Smart App. 

When you do come to replace the filter there are four options to choose from. There's the original 'Breeze' filter that the purifier comes fitted with as standard, and then three additional filters that focus on removing odour, pollen, or bacteria and viruses.

However, these filters aren't cheap. The smaller air purifiers we've tested tend to average around £30 for replacement filters, but the AEG AX91-604GY is a large air purifier capable of cleaning the air in large rooms, and as such its filters are pretty sizeable too. That means a replacement AEG AX91-604GY filter will set you back around £100 as of writing. Ouch.

Verdict

Overall, the AEG AX91-604GY Connected Air Purifier is one of the best air purifiers for large spaces that I've tested. So, if you have large rooms or an open-plan home, then this could well be a great choice for you. 

That powerful fan, high CADR, and spiralling 'AirSurround system' do a great job of circulating the air in a large space to make sure the AX91-604GY is filtering every corner of the room. And it has a sizeable air filter with 5 stages of air purification to clean that air when it reaches the purifier.

The Smart mode is a brilliant feature that makes managing air quality super simple, the AX91-604GY is quiet on all but its highest fan speeds, and its controls are a dream to use, offering the best and easiest user experience of any air purifier I've tested. 

The air purifier's six-colour air quality indicator is also a great touch, as is the fact the machine is Wi-Fi compatible and can be paired with AEG's Wellbeing App for extra air quality data and functionality, as well as offering integration with Google Home.

The AEG AX91-604GY Connected Air Purifier's stylish design is another plus point. 

However, its premium feel is matched by a premium price point. This air purifier is a significant investment upfront, and although relatively low energy usage and that power-saving automatic mode mean running costs are fairly low, you do need to factor in the ongoing cost of those expensive replacement air filters. At £100 a pop as of writing, they certainly aren't cheap.

And, whilst a lot of consideration has gone into the AX91-604G's design to make it feel a lot less bulky than it might otherwise do, it is still a large and cumbersome appliance in the grand scheme of things. 

To my mind, this is an air purifier built for use on one level of the home rather than an appliance you'll want to carry up and down the stairs frequently. 

If you have a home with small rooms the AX91-604G probably isn't your best option – in that case, I'd recommend the less powerful but far more compact Levoit Core 300S air purifier or the mid-sized and super-responsive Blueair Blue Max 3250i air purifier instead. 

However, with the AEG AX91-604GY Connected Air Purifier powerful enough to filter the air in spaces up to 129m2, it is the perfect option for a one-level apartment, open-plan home, or any house with large rooms.