How loud is a Dyson air purifier?
A Dyson air purifier lists from 24 dB in Sleep mode on the HushJet models to 63 dB(A) at maximum flow on the Hot+Cool heaters. Those figures appear under several Dyson labels that cannot be set side by side.
Three kinds of figure turn up. Dyson's product pages, in the US where they have one and in the UK otherwise, show a "Sound level (Max)" row and a "Sound level (Quiet Mode)" row. The US technical sheets give a sound level at minimum and maximum flow rate. The Big+Quiet BP03 sheet gives sound power at two named airflow settings.
Not one Dyson page or sheet says how far away the microphone sat or which test was followed. Within one group the figures can be read against each other with care. Across groups they cannot, and the BP03's sound power, which differs from sound pressure, sits furthest apart of all.
Which Dyson air purifier is the quietest?
The HushJet Big+Quiet Cool Pure+ Formaldehyde and the HushJet Purifier Compact share Dyson's lowest figure, 24 in Sleep or Quiet Mode. At full power the Compact is lower, 41dB in Dyson's US page copy against 51dB for the Big+Quiet.
The pairs below all come from the two rows Dyson's product pages use, Quiet Mode first and Max second. The US page is the source where Dyson prints a figure there, and the UK page where it does not. US prices are from dyson.com on October 21, 2026.
- 24 and 51 Decibel: HushJet Big+Quiet Cool Pure+ Formaldehyde, US page, $1,099.99.
- 24 and 42 dBA: HushJet Purifier Compact HJ10, UK page, $349.99. Its US page copy says 24dB and 41dB instead.
- 38 and 56 dBA: Big+Quiet Formaldehyde BP04, UK page, $1,199.99.
- 46 and 62.4 dBA: Purifier Humidify+Cool PH2 De-NOx, UK page, $1,099.99.
- 50 and 61.5 dBA: Find+Follow Purifier Cool PC3, US page, $849.99.
- 50 and 61.4 dBA: Purifier Cool PC1 ($549.99) and Purifier Cool PC2 De-NOx ($849.99), UK pages.
The HP2 De-NOx is missing from that list on purpose. Its UK table carries two different maximums, so its figures here come from the US sheet instead.
How quiet is the Dyson Big+Quiet?
The Big+Quiet BP04 lists 38 dBA in Quiet Mode and 56 dBA at max on Dyson's UK page. The BP03's US sheet gives sound power instead: 39.8 dBA at airflow setting 2 and 56 dBA at setting 10.
Dyson sells the range on low noise. The US BP04 page calls it "Our quietest, most powerful and advanced air purifier" and says "Night mode is 50% quieter than any other Dyson purifier.***", footnoted "***Excluding SP01." The UK FAQ adds that the BP04 "is engineered to be up to 50% quieter than previous Dyson models".
The number 56 turns up three times with three meanings. The BP03 sheet calls it sound power at setting 10, Dyson Australia prints "Decibel Level 56 dB(A)" for both models with no setting, and the UK calls it the BP04's "Sound level (Max)". Dyson never says these are one measurement, so we keep them apart.
Is the Dyson HushJet quieter than the Big+Quiet?
Yes, on Dyson's matching spec rows. The HushJet Big+Quiet lists 24 in Quiet Mode and 51 at max on its US page, against 38 and 56 dBA for the Big+Quiet BP04 on the UK page. Neither row names a test.
Dyson writes the HushJet figures as "Decibel" and the BP04 figures as dBA, a small difference that still means the two pairs are only loosely comparable. Its shop listing now describes the HushJet as a "HushJet™ silencer for Dyson's quietest, most powerful purifier", wording the BP04 page also uses for itself.
On paper the HushJet Big+Quiet also covers more ground, 916 sq ft against the BP03's 264, and costs $100 less than the BP04. The BP04 keeps the longer filter life: Dyson rates its HEPA filter for up to 11 years, against up to 18 months for the HushJet's filters.
How loud are Dyson's bladeless tower purifiers?
Dyson's bladeless tower purifiers list Max 46 or 50 dB(A) at minimum flow and 61.4 to 63 dB(A) at maximum flow. Those figures live on US technical sheets on Dyson's commercial site, not on the product pages.
Each line gives the minimum flow figure, then the maximum flow figure, from Dyson's US sheet.
- PC1: Max 50 dB(A), then Max 61.4 dB(A). $549.99.
- PC2 De-NOx: Max 50 dB(A) in both modes, then Max 61.4 dB(A) in Fan mode and Max 61.5 dB(A) in Purifier mode. $849.99.
- HP1: Max 46 dB(A), then Max 63 dB(A). $659.99.
- HP2 De-NOx: Max 50 dB(A), then Max 63 dB(A) in Fan mode and Max 62 dB(A) in Purifier mode. $949.99.
- TP10 Gen1: 42.6 to 50.0 dB(A) at speed 4, then 57.8 to 61.4 dB(A) at speed 10. $379.99.
- HP10 Gen1: 40.0 to 46.0 dB(A) at speed 4, then 59.0 to 63.0 dB(A) at speed 10. $629.99, out of stock.
The heaters, HP1 and HP10, carry the lowest minimum flow numbers, 46 at the top of their range where the coolers list 50. Dyson gives no reason. The older TP07 and TP09 sheets write their figures in dB without the A, Max 46 dB at speed 4, so we leave them out of this list.
What does "Max 50 dB(A)" mean on a Dyson spec sheet?
On a Dyson spec sheet, "Max 50 dB(A)" is the upper end of a measured range. The Gen1 TP10 sheet prints both ends, "Min 42.6 dB(A); Max 50.0 dB(A)", at speed 4, which it calls the minimum flow rate.
Read that way, the newer sheets for the PC1, PC2, HP1 and HP2 show only the top of each range and leave out the speed. The Gen1, TP07 and TP09 sheets all tie minimum flow to speed 4, so that is likely what the newer sheets mean too, though Dyson does not say so.
The spread inside one speed is wide. The TP10's two ends at speed 4 sit 7.4 dB apart and the HP10's sit 6 dB apart. Dyson does not say whether that range reflects different units, microphone positions or filters, so we quote the Max figure, which is the one Dyson keeps on every sheet.
None of these sheets has a figure for speeds 1 to 3. A tower turned below speed 4 may well be quieter than the minimum flow number, but Dyson publishes nothing to show how much.
How loud is the Dyson Purifier Humidify+Cool?
The Dyson Purifier Humidify+Cool PH2 De-NOx lists 46 dBA in Quiet Mode and 62.4 dBA at max, but only on Dyson's UK page. Its US page, US manual and Dyson's commercial site give no figure.
The UK table also repeats the top number as "Sound level 62.4 Decibel". Dyson does not say whether humidifying changes the noise. The US manual describes Night mode only by its settings: the machine keeps monitoring "only using its quietest settings" with the screen dimmed, and with Auto purify or Auto humidify on, airflow drops to a range of 1 to 4.
What does Night mode do on a Dyson purifier?
Night mode on a Dyson purifier keeps it sensing and cleaning the air while holding it to its quietest settings and dimming the display. Dyson attaches a figure to this mode on only a few models.
The Find+Follow PC3 page promises "50% quieter in Sleep mode***", footnoted "***50% quieter compared to max fan speed." The same page lists 50 dBA in Quiet Mode and 61.5 dBA at max, 11.5 dB apart. A gap of about 10 dB is usually heard as roughly half the loudness, so the claim fits Dyson's own pair.
Dyson's naming wanders. The tower manuals and remotes say Night mode, the HushJet pages say Sleep mode, and the spec tables say Quiet Mode, and Dyson never confirms these are one setting. Our page on quiet and sleep modes sets out how other makers use the same words.
Dyson's US and UK figures differ mainly because each store fills in different spec rows, and a few UK rows clash with Dyson's own sheets. The HP2 De-NOx is the clearest case.
The UK HP2 page shows "Sound level (Max) 56 dBA" and "Sound level (Quiet Mode) 38 dBA", the exact pair the UK gives the BP04, and in the same table "Sound level 63 Decibel". The US HP2 sheet gives Max 63 dB(A) at maximum flow in Fan mode. We used the sheet; the UK pair looks like a row carried over from the BP04.
Smaller gaps exist too. The HushJet Compact is 41dB at maximum in US and UK page copy but 42 dBA in the UK spec table. The BP04 gets a figure only in the UK and Australia, and the PH2 only in the UK, so a US buyer has to look abroad for either one.
Are Dyson's tower purifiers quiet enough for a bedroom?
No, not on Dyson's sheets at the lowest flow they cover, where the towers reach 46 to 50 dB(A) at speed 4 or minimum flow. Dyson publishes nothing for speeds 1 to 3, which may be quieter.
That leaves the HushJet machines as the only Dyson purifiers with a published figure meant for sleep, 24 dB. Whether a tower at its lowest speeds suits a given sleeper depends on the person, the room and how quiet a bedroom needs to be, none of which Dyson's sheets can settle.
