The new Dyson Big+Quiet still leaves a lot to be desired

The new Dyson Big+Quiet still leaves a lot to be desired

This month, Dyson debuted its new Big+Quiet range of air purifiers. Offering a less-than-discreet, almost extraterrestrial appearance, we have again found Dyson’s new device to, in true Dyson fashion, over-promise and under-deliver when it comes to air purification. Read on to learn more.

Our review of Dyson products: an overview

Here at Eoleaf, we have previously been outspoken regarding Dyson’s lack of transparency and disappointing technological prowess when it comes to air purification. As air purification experts, our observation is that, as a huge multinational technology company, Dyson saw a consumer demand for air purification products and decided to throw its hat in the ring. Despite their products’ popularity due to their keen eye for design, during our analysis, we found Dyson’s air purification capacities in its Hot+Cool 2-in-1 air purifier (air purification + heating/cooling) to be severely disappointing. And this refers only to the information we were able to find on their website – many of their devices’ technical specifications are not disclosed or made available to the public.

During our research, we found that, when it comes to air purification, Dyson’s Hot+Cool air purifier offers nothing more than a HEPA-certified filter and an activated carbon filter. At Eoleaf, our devices come equipped with 8 different air purification technologies in order to combat all types of indoor air pollution. Here are the technologies our devices contain that Dyson’s don’t:

Furthermore, we always recommend that customers be wary of 2-in-1 or 3-in-1 devices. An air purifier that offers heating, cooling, and/or humidication, although seemingly convenient, actually decreases your air purifier’s efficiency and your filter’s longevity. 2-in-1 and 3-in-1 devices experience dramatic temperature and humidity fluctuations, both of which damage the microfibres in an air purifier’s filters. This ultimately reduces air filtration efficiency and requires more frequent filter changes. Would we love to offer a product that helps customers purchase less devices? Of course we would! However, it is simply not possible to offer both technologies and deliver high quality air filtration. When it comes to your health and breathing indoor air pollution, the only big promises made should be those regarding the filtration of your air. This is why we recommend investing in a device exclusively devoted to the removal of indoor air pollution.

The new kid on the block: Dyson’s Big+Quiet

Recently, Dyson announced its new Big+Quiet air purifier. This product focuses solely on air purification and, unlike Dyson’s other air purifiers, does not offer 2-in-1 or 3-in-1 heating/cooling/humidification capabilities. The Big+Quiet is designed for professional environments like offices, classrooms, and hotels. According to the product’s website, it filters rooms up to 100m2 in size and is advertised at a price point of £569.99 in the UK and 999.99€ in Europe.

Two people sitting in a room next to Dyson's Big+Quiet air purifier

How is the Big+Quiet different? This one has been ‘re-engineered’ to be quieter than their previous models, offering 55.6 dB when running at its fastest fan speed (this device has only two fan speeds). They have also made one technical specification available that had not been made available with their previous products: their activated carbon filter contains 430,000 m2 of activated carbon. However, this figure means nothing without knowing the weight of the filter (as you will see in the chart below, the activated carbon filter in our AEROPRO 150 contains 1.28 kg of activated carbon). Again, this shows Dyson’s penchant for flashy marketing over raw, comparable, industry-standard data.

Here is a brief technical specification comparison between Dyson’s Big+Quiet and Eoleaf’s AEROPRO 150, our professional model:

Dyson’s Big+Quiet

Eoleaf’s AEROPRO 150


HEPA filter, activated carbon filter

Prefilter, bamboo fibre filter with antibacterial coating, HEPA filter, activated carbon filter, photocatalysis, UVC sterilisation, ionisation

HEPA filter

Yes, H13 filter that captures 99.95% of pollutants down to 0.1 microns

Yes, H13 filter that captures 99.97% of pollutants down to a size of 0.01 microns

Activated carbon filter

Yes, surface area of 430,000 m2

Yes, weight of 1.28 kg


Not communicated

670 m3

Air circulation angle



Fan speeds



Standby power consumption



Min and max noise level

43 dB (speed 1) to 55.6 dB (speed 2)

30 dB (speed 1) to 60 dB (speed 5)

Filter lifespan

Not specified

12 months


11.57 kg

11.8 kg

Size (H x W x L in mm)

830 x 415

840 x 312.5

Room size

Website says 100m2, technical specifications say 70m2


Smart features

Yes, connectivity with the MyDyson app

Yes, connectivity with the Tuya Smart app, Bluetooth terminal remote control display, voice commands, gesture controls

Our analysis

Filtration technologies

Considering the price at which this product is offered, it again seems that Dyson is overcharging for an air purifier that only contains a HEPA filter and an activated carbon filter. Why pay so much for a device that offers the two essential technologies that are (and should be) found in almost every air purifier, but nothing more? Dyson's Big+Quiet air purifier and its two filters

Eoleaf’s AEROPRO 150, at a lower price point, offers 8 different filtration technologies designed to trap and filter any type of indoor air pollution. Considering the price at which Dyson sells their Big+Quiet, why settle for less filtration technologies? As a matter of fact, our AEROPRO 100 covers the same surface area as the Dyson Big+Quiet but is 30% cheaper.

Eoleaf's 8-step filtration system

Still no CADR

Similarly to our last article, we continue to be disappointed by Dyson’s refusal to use the Clean Air Delivery Rate (CADR) standard used by all other companies offering air purification devices. But we are not surprised: this is part of Dyson’s general policy of not releasing raw metrics or meaningful ways to compare their products to the competition. The CADR is an essential metric which provides consumers with a way to compare filtration capacity between other brands. Instead, claiming that CADR is ‘insufficient’, Dyson relies on its own ‘POLAR test’ to determine its devices’ efficiency. We again ask the question: how is it possible for consumers to compare their device’s efficiency with other devices on the market if it does not use the same standards as everyone else? This brings us to the conclusion that either their CADR has not been tested (and, thus, the efficiency of their devices unverified), or their CADR rating is low, so it is best to hide it from the public.

At the very least, Dyson could release both the CADR along with the POLAR result.

Aesthetics and room size

Now, let’s compare some aesthetic specifications between Dyson’s Big+Quiet and Eoleaf’s AEROPRO 150. As mentioned above, we have chosen the AEROPRO 150 for comparison since it is our professional model, just like the Big+Quiet is geared towards larger, professional spaces. But, in truth, the Big+Quiet is much more comparable to our medium-range device: the AEROPRO 100.

Size and weight of these two devices is comparable with the Big+Quiet being a bit wider. Aesthetically, it has been redesigned to include a ‘motor bucket’ in order to reduce turbulence, pressure, and noise. As far as noise is concerned, the Big+Quiet is a success. But it only comes with two speed levels, a fact we found to be surprising. Our models use five speed levels to adapt to the pollution rate using Automatic mode.

However, we find the design to be anything but discreet, and for us, having an air purifier that blends perfectly into the background, especially in professional spaces, should be a priority. This way, neither employees nor customers/clients/patients are disturbed by its presence.

One important detail that struck us was the fact that the Big+Quiet is advertised as being capable of filtering the air in a room of 100m2. As Dyson’s professional model, it is designed for ‘large, professional spaces’. However, their technical specifications of the Big+Quiet indicate that the device can only filter the air in spaces of up to 70m2! This is a huge difference, and only the eagle-eyed consumer will find this information on their own. That said, the Big+Quiet is sized for a significantly smaller room than one might think: for comparison, our AEROPRO 100 model, our medium-sized device, filters the air in rooms up to 80m2.

Dyson's Big+Quiet technical specifications


Air outlet and circulation

Finally, the Big+Quiet device uses a diagonal air outlet with an air circulation angle of only 50°.

Dyson's Big+Quiet horizontal airflow


This is indeed an improvement from Dyson’s Hot+Cool device which offered a strictly horizontal air outlet. This new diagonal air outlet still remains problematic for two reasons: 1) it fails to account for the fact that purified air is slightly heavier than polluted indoor air and 2) most fixtures will impede the fan’s airflow.

  1. When purified air is released back into the room diagonally, all of the air above the air purifier will remain unfiltered. The best way to circulate purified air is with a vertical air outlet because this encourages improved mixing of all the air in the space, including the air above the device.

  2. When purified air is recirculated horizontally or diagonally, any furniture present in the room will impede the fan’s airflow. It is essential to have unobstructed airflow and an air purifier should be placed away from obstacles, out of corners, etc. Due to the Big+Quiet’s horizontal air outlet, proper placement will be very difficult. This is why all of Eoleaf’s air purifiers are designed with a vertical air outlet and a 360° air circulation angle: this way, most furniture does not get in the way.

Eoleaf's vertical airflow

In summary

Considering the fact that they are a multinational household appliance company with immense resources, we continue to be disappointed by the quality of Dyson’s air purification products and the lack of transparency regarding their performance. We feel that a consumer’s money is much better invested in a device that will provide the best quality air purification, especially for those who are most vulnerable and are looking to protect themselves from air pollutants that may aggravate their respiratory health conditions. We are proud of the products we offer here at Eoleaf, and we know that we provide the best air purification technologies on the market, protecting you and your family from the dangers of indoor air pollution.

Eoleaf's AEROPRO 150 air purifier

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