Big+Quiet Formeldehyde, the new “big” air purifier from Dyson

At first glance it looks like some sort of gramophone. And instead it is the new Dyson Purifier Big+Quiet Formaldehyde purifier (well, the name is not exactly easy to remember), ideal for very large environments (like lofts, for example) and equipped with an enhanced purification system and is very silent. We tried it for over two weeks, here’s how it went.

The main features

Dyson Purifier Big+Quiet Formaldehyde is a cylinder approximately 80 centimeters high and easy to transport because it has wheels. Once turned on, the purifier does everything by itself (automatic mode is activated by default) and adjusts the flow based on the air quality of the room in which it is placed; it is obviously always possible to increase or decrease it either via the remote control or via the connected app. The new purifier projects the purified air at angles of 0, 25 or 55 degrees and thanks to a unique software algorithm makes it oscillate in ascending and descending micro-movements imitating the natural movements of the breeze.

A project that lasted years

Dyson engineers explain that the new purifier guarantees up to 87 liters per second of purified air with a radius of over 10 meters and that the compressor has been redesigned ensuring silent operation (at maximum, 56 dB of noise). The filtration system has also been rethought: it has three phases (HEPA H13 filter, K-Carbon filter and selective catalytic oxidation filter) and is capable of capturing up to 99.95% of ultrafine particles. And again: it removes three times as much nitrogen dioxide (emitted from cooking food or road pollution) and permanently destroys formaldehyde, with a HEPA filter life of five years. To solve the problem of weak air flow in the areas furthest from the purifier, the engineers developed a new low-pressure air delivery system with cone aerodynamics, which – they explain – uses an effect called “Cooanda” to join two air flows on a “smooth” surface.

How does it work

There is an LCD display on the purifier that shows the air quality in the room in real time. Through the remote control or through the app it is also possible to consult the levels of fine and fine particles PM 2.5 and PM 10, formaldehyde, volatile organic compounds, nitrogen dioxide, temperature and humidity thanks to sensors that cross-check the data every second. The machine can completely purify the air of a large room in about an hour. Through the app it is also possible to program the appliance or request replacement filters. Compatible with Alexa and Google Home voice assistants but not with Apple’s HomeKit; However, on iPhone it is possible to use Siri shortcuts. In our test we were very satisfied, especially with the purification performance and the silence of the device. Dyson Purifier Big+Quiet Formaldehyde has a price of 999 euros.

Pros and cons


  • Powerful, silent, simple to use air purifier
  • In one hour it completely purifies the air in a large room


  • Not compatible with Apple’s HomeKit ecosystem (but can still be controlled via Siri)