Last Updated on October 24, 2026 by Umar Farooq
How loud is a dehumidifier? The makers’ own figures for portable compressor units run from about 38 dB to 57 dB(A), quoted at one metre, and in a real room the same machine often sounds louder than its label.
That gap is the whole story. The label is a number from a test setup; your hallway has a hard floor, a bare wall and a bed two steps away.
The figures manufacturers actually publish
Noise on a spec sheet is normally given in dB(A), which is a sound level weighted towards what the human ear picks up. Meaco’s manual states its figure plainly as “noise level at one metre”. That is the useful convention: it tells you how far away the microphone was.
Here is what I could trace to pages I opened. These are manufacturer figures, not my own measurements, and I have not seen an independent test I could open and quote.
| Source | Unit type | Published figure |
|---|---|---|
| Meaco ABC 10L/12L/20L manual | Compressor | Maximum 40, 40 and 44 dB(A) at one metre |
| QuietSpecs round-up of maker figures | Full-size compressor, figure per fan speed | 43 to 57 dBA (Frigidaire 43/46/49 dBA low/medium/high on one model; 57 dBA on high on another) |
| Same page | Compressor, single or unnamed speed | 38 to 48 dB |
| Same page | Thermoelectric mini unit | about 33 dB |
Read that as a range: roughly 38 to 57 dB for compressor units, and lower for small thermoelectric ones, which have no compressor to hear. I have no figure for desiccant units that I opened, so I am not going to invent one. If you are choosing between types, desiccant versus compressor covers what each is built for.
One catch from the same QuietSpecs page: it says none of the makers it checked state a measuring distance or a test standard. So a number with no “at 1 m” next to it is a number you cannot fully compare.
What a few decibels mean in a room
Decibels are logarithmic. The US NIOSH puts it simply: a sound 10 dB louder than another is ten times more intense.
So the difference between a 40 dB(A) unit and a 51 dB(A) unit is not a small step. By that rule, 11 dB is more than ten times the sound intensity. (That is my arithmetic from the NIOSH statement, and intensity is not the same thing as how loud it feels, which is harder to put a number on.)
Two practical consequences:
- Small gaps on a label are not small. A 44 against a 40 is a real difference, and a unit’s high fan speed against its low one can be several dB apart.
- Distance changes the reading. Sound falls with distance, and that is why the stated measuring distance matters. A figure taken at one metre will read higher if your pillow is half a metre from the machine.
For bedrooms the WHO guideline is below 30 dB(A) at night, which no compressor figure above reaches. I go through what that means for sleeping in the quiet dehumidifier for bedroom guide, so I will not repeat it here.
Why yours sounds louder than the label
The rating is the machine on its own. What you hear is the machine plus everything it touches. These are the usual reasons, most likely first. This is my judgement from how these units behave, not measured effects.
- A hard floor. Compressor vibration passes into boards or tiles, and the floor acts as a sounding board.
- A hollow perch. A cupboard, a shelf or a stack of boxes resonates. Put a unit on one and it becomes a speaker cabinet.
- A wobbling base. A unit that rocks on an uneven floor hums against it. Meaco’s manual asks for a stable, level surface for safety; it also happens to be the quiet choice.
- A loose bucket or filter cover. A bucket or filter cover that is not seated is a classic rattle.
- A dirty filter. Meaco’s manual says the filter should be cleaned at least every two weeks and that a blocked one stops it collecting water. It makes no noise claim, and I have not measured the effect, but a unit working against a clogged intake is not going to be quieter for it.
- Distance and walls. Closer to you, closer to a wall, closer to the bed: all louder than the one-metre rating.
If the noise is a change (a new rattle, a knock, a grind) then you are in fault territory, and why a dehumidifier makes loud noise goes through the sounds one by one.
Quieten it in five moves, cheapest first
- Level it and seat it properly. Put it on a flat, stable floor so it sits evenly, as the Meaco manual’s “stable, level surface” instruction asks. Press the bucket and filter cover home.
- Get it off hollow things. The floor beats a shelf. A thick mat or rug between unit and boards is the next improvement; I am recommending this from experience, not a measurement.
- Clean the filter. Fortnightly, per the manual. It is free and it stops the unit working harder than it should.
- Move it away from where you sleep. Meaco suggests a central position such as a landing or hallway with interior doors open. That serves drying and noise at once: see where to put a dehumidifier.
- Run it when you are not in the room. A timer or a daytime run means you hear it least. Whether you need one in the bedroom at all is a separate question, answered in do I need a dehumidifier in my bedroom.
The rating is the floor, not the ceiling
My opinion, and the reason I trust it: treat the dB(A) on the box as the quietest your unit will be. Makers test under conditions they control, many do not state the distance, and a bare floor or a hollow shelf adds noise the test never had. Read the label for comparison, then judge a unit by where it will actually stand.
FAQ
How loud is a dehumidifier in dB?
Published figures I could trace for compressor units run from about 38 dB (a single-figure hOmeLabs unit on QuietSpecs) and 40 dB(A) at one metre (Meaco) up to 57 dBA on high speed (one Frigidaire model, as listed by QuietSpecs). Small thermoelectric units publish around 33 dB.
Is a dehumidifier louder on a higher fan speed?
Makers that publish a figure per speed show it rising. One listed Frigidaire model is 43, 46 and 49 dBA on low, medium and high.
Why is my dehumidifier louder than the box says?
The box figure is taken at a set distance, usually one metre where it is stated. A hard floor, a hollow surface, an uneven base, a loose bucket or being closer than a metre will all make it sound louder.
Does a decibel number double when the noise doubles?
No. The scale is logarithmic: 10 dB more means ten times the sound intensity, per NIOSH. How loud that feels is a separate matter.
Can a dehumidifier be silent?
Not on any figure I found. The lowest published number was about 33 dB for a thermoelectric mini unit, which is quiet but not silent.
