How loud is a dehumidifier? Noise levels explained

What dB(A) means

Decibels measure sound pressure on a logarithmic scale. The A in dB(A) means the reading is weighted to match how human hearing responds to different pitches. Because the scale is logarithmic, small numbers matter: an increase of about 10 dB is commonly described as sounding roughly twice as loud, and 3 dB is a doubling of sound energy.

So a unit quoted at 38 dB(A) is noticeably quieter than one at 45 dB(A), even though the numbers look close.

Typical figures by type

Small compressor dehumidifiers on low speed are often quoted in the mid to high 30s dB(A), rising into the 40s on high. Meaco quotes 38 dB for the Arete Two 20L, and the Bosch Dry 1000 is listed at 34 dB(A). Desiccant units have no compressor, so they lack the hum and click, but their fans and heaters still make a steady whoosh. The EcoAir DD1 Classic MK6 is listed with a 34 dB(A) quiet mode.

Laundry and boost modes run the fan on high and are always louder than night or quiet modes.

Room size changes the experience too. In a large living room, a unit at 45 dB(A) can fade into the background; in a small bedroom with the door closed, the same unit can dominate. If the dehumidifier will run near where you sleep, look for a stated figure in the 30s on its lowest speed or night mode.

Why stated figures differ from what you hear

Makers may measure at different distances, in different rooms, and on different fan speeds. A figure taken a metre away on the lowest speed in a quiet test room will sound quieter than the same unit on high in a small room with hard floors. Hard surfaces reflect sound; carpets and curtains absorb it.

The type of sound matters too. A steady fan whoosh is easier to ignore than a compressor that starts and stops, or a slight rattle. Some people find a low hum harder to sleep through than a higher, steadier sound.

If two models you are comparing quote figures measured in different ways, treat the comparison as rough. A useful check is whether the maker says which fan speed the figure applies to. A model that quotes both a low and a high figure gives you a clearer picture than one that quotes a single number.

How to run a dehumidifier quietly

Use night or quiet mode if it has one, which lowers the fan and dims the lights. Put the unit on a firm, level floor or a rubber mat, not on bare floorboards that can resonate. Keep it a little away from walls and furniture so it does not vibrate against them.

Run it on high during the day while you are out, so it reaches the target humidity, then switch to quiet mode at night. A unit that is slightly larger than you need can often maintain the room on a lower fan speed. Our guide on where to put a dehumidifier has placement tips.

• Use night or quiet mode in bedrooms
• Stand it on a firm, level surface or rubber mat
• Keep a gap from walls and furniture
• Run on high during the day, quiet at night
• Clean the filter so the fan is not straining

See quiet dehumidifiers for bedrooms →

When a noise means a fault

A new rattle, grinding or loud buzzing is worth checking. Unplug the unit and look for something touching the fan, a loose panel or a filter out of place. A clogged filter can make the fan work harder and louder; see how to clean a dehumidifier. If the compressor clicks on and off very frequently, or a noise continues after cleaning, contact the maker.

Frequently asked questions

Are dehumidifiers loud? Most are quoted between about 34 and 50 dB(A). On a low setting many are quiet enough for a bedroom; laundry and boost modes are louder.

How loud is a Meaco dehumidifier? Meaco quotes 38 dB for the Arete Two 20L. Check the stated figure for the exact Meaco model you are considering.

Are desiccant dehumidifiers quieter? They have no compressor, so no hum or click, but their fan and heater still make noise. Some list low quiet-mode figures.