Portable air conditioner noise levels explained

For a living room, a portable air conditioner rated 55 dB or below is quiet for the category. For a bedroom, aim for about 50 dB or lower, use sleep mode and place the unit as far from the bed as the hose allows. Over 60 dB is best kept for daytime use or rooms you are not sleeping in.

Decibels (dB) are measured on a logarithmic scale. Every 3 dB increase doubles the sound energy, but your ear does not hear it as double: a rise of about 10 dB sounds roughly twice as loud. That is why a 50 dB unit and a 60 dB unit are clearly different, while 52 and 54 dB are hard to tell apart.

Manufacturers quote A-weighted decibels (dB(A)), which match how the human ear responds to different frequencies, measured about a metre from the unit.

Why are they louder than a split system? The compressor, which makes most of the noise, sits in the same room as you, along with two fans. A split system keeps the compressor outdoors. Inverter compressors run at variable speed instead of switching on and off, which makes them quieter and avoids the sudden clunk when the compressor starts.

The World Health Organization's guideline for continuous noise in a bedroom is around 30 dB. No portable air conditioner meets that at one metre, but you rarely sleep at one metre. Doubling the distance cuts the level by about 6 dB, and a closed door between hose and bed helps too.

• Pre-cool. Run the unit at full speed for an hour before bed, then switch to sleep mode.
• Use sleep mode. It lowers fan speed and lets the temperature drift up a degree or two overnight.
• Pick the right size. A larger unit can run at lower fan speed for the same cooling.
• Mind the compressor click. Sudden start-up noise wakes people more than steady noise. Inverter models avoid it.

These are the lowest manufacturer noise ratings among the portable air conditioners in our catalogue, using figures and prices recorded on 15 April 2026. Stock changes quickly, so check the retailer before you decide.

For more, see the best portable air conditioners shortlist or compare models side by side.

1. Level it. A unit that rocks vibrates against the floor. Check with a spirit level.
2. Add a mat. Rubber or thick carpet absorbs vibration.
3. Secure the hose. A loose hose rattles against the window kit; strap it in place.
4. Clean the filter. A clogged filter makes the fan work harder and louder.
5. Give it space. Leave about 50 cm clear around the unit so air is not choked.
6. Use a lower fan speed. Run high to cool down, then drop to low or sleep mode.
7. Seal the window kit. Whistling and buzzing often come from gaps around the panel.

The rating on the box is a manufacturer figure measured in a test room. Our free sound meter uses your device's microphone to read the level where you actually sit, and shows how it compares with the ratings above. A phone microphone can be a few decibels out, so use it to compare positions and modes rather than as a precise measurement.