Quiet Portable Air Conditioners

Portable air conditioners make a lot of noise.

You wouldn’t know this looking at the product descriptions for some of the most popular units on the market. It’s not uncommon to see units marketed as having “Quiet Operation”. One model lists its noise output as being only 44 dB, with a graphic on its packaging showing how this is a noise level that's somewhere in between that of a library and an office.

Under what conditions did this model produce only 44 dB? On cooling mode or fan only mode? At what distance was the noise level measured? Certainly not anywhere close to the actual AC unit.

Our testing revealed that in the area immediately surrounding a portable AC unit (at a distance of 2 ft.) the average unit produces about 60 dB of noise.

At longer distances (at 10 ft.) most units still produce about 55 dB of noise.

These measurements were taken with models operating on cooling mode and maximum fan speed. The same model that claimed a noise output of only 44 dB was measured at 59.5 dB at 2 ft. and 54.2dB at 10 ft. on cooling mode and high fan speed.

At lower fan speeds, noise output is further reduced.

However, the actual quality of the noise changes quite a bit.

You see, portable AC units primarily make only two different types of noise:

• fan noise and
• compressor noise

Portable AC unit fan noise sounds just like fan noise on any other appliance with fans – a clean white noise with a “shhhhhh” sound.

Compressor noise is hardly a clean white noise. In fact, it’s far from it.

Compressor noise varies from a low frequency buzzing sound (“bzzzzzz”) to a higher frequency buzzing sound.

On high fan speed the AC unit’s compressor noise is masked by its fan noise.

On low fan speed this is no longer the case.

So, while the measured dB on low fan speed is less, the compressor noise is no longer masked. Instead of hearing primarily fan noise as you do on high fan speed, you now hear the unpleasant buzzing noise of the compressor.

Thus, the vast majority of consumers will almost always run their portable AC units on high fan speed. This is really the only way to tolerate the underlying unpleasant noise generated by the unit’s compressor.

And, on that high fan speed, the noise level for most models is at approx. 60 dB.

The table below shows the exact measurements for a few select units on the market, measured 2 ft. away from each unit:

Note how all models listed here produce just about the same amount of noise on high fan speed.

No matter the manufacturer. No matter the model. Noise output is very similar for all units on the fan speed you're likely to use the most - high fan speed.

New compressor technology

To round out this analysis, we briefly need to talk about new compressor technology.

Both the Midea Duo and LG LP1419IVSM are equipped with inverter (variable speed) compressors.

Most other portable AC units on the market are equipped with single stage compressors.

Inverter compressor models run at lower power with more of a drop in noise output on lower fan speeds. Single stage compressor models run at the same power level with much less of a drop in noise output on lower fan speeds.

When it comes to raw noise output, inverter compressor models are "quieter" on lower fan speeds.

The problem is that they produce the same unpleasant buzzing noise as single stage compressor models.

And so, just like a single stage compressor model, you won't want to run an inverter compressor model on lower fan speed. Instead, you'll want to run it on high fan speed to better mask the unpleasant noise of its compressor.

Conclusion

Portable air conditioner noise output is a fairly simple topic.

You really only need to know three things about it: