A quiet window air conditioner is a rare and wonderful thing. One of the most common complaints about window air conditioners is the noise they make. Consumers who shop only by price or cooling capacity are often surprised when their “best buy” becomes an irritating intrusion that wakes them up from sleep or makes them crank up the television every time it turns on. In this article we look at how to get that noise down, which are the quietest window units, and offer some quiet window unit buying advice.
The reason window air conditioners produce noise is because they create vibrations. Some of this is intentional and unavoidable, some of it isn’t. The two main areas of “designed noise” come from the compressor, which is a type of pump, and the fan which blows cool air. If you wish to distinguish between the two, turn on the fan with the cooling setting at the minimum (or off if possible) and you will hear the fan alone. Adding the cooling function turns on the compressor and you will hear a noticeable increase in noise level. The noise from worn bearings in a compressor will be louder and older units are noisier because of wear as well as older manufacturing practices. There is little you can do except replace them to lower the noise level.1
Fans will increase sound production if they are dirty, so cleaning the blades is a good idea.
There are two main sources of unintended noise. The first, and most important is noise generated by a poor fit to the window opening. When the AC unit has room to move, vibrations from the compressor are magnified by the case or even the window frame. A bad fit or loose mounting is the most common cause of unacceptable noise. You can test for this by grabbing the AC and seeing if you can wiggle it in the opening. A tight fit won’t allow any apparent motion.
A tight fit also helps with the second unintended source of noise: noise transmitted from outside the building through the air conditioner. A closed window blocks a great deal of traffic and ambient noise – you may not even realize it if you are used to having the windows closed. However, a window air conditioner provides an almost uninterrupted path from outside to inside and noise is carried along. You can avoid this if you can mount it away from busy streets or other outside noise sources, perhaps in another window.
Other noises, such as whistling or buzzing usually indicate a mechanical flaw in need of repair.2
Who makes a quiet window air conditioner?
There are a few things to note. The first is that fan speed matters. Running an AC on high is noisier than running it on low speed. The second is that the size of the unit makes a difference. In general, the larger the cooling capacity, the more noise a window air conditioner generates.
Here are some of the more quiet window air conditioners on the market today. Note the db noise levels listed below for each unit are for fans on the low setting. Higher fan settings will be louder.
- Frigidaire FRA065AT7 6000BTU 47.6db
- Frigidaire FAX052P7A 5000BTU 48db
- Sharp AF-Q60PX 6300BTU 53db
- Sunpentown WA-6591S 6500BTU 50db
All of the units above are smaller, under 8000BTUs. The larger Frigidaire FAS256R2A which has a 25000BTU rating has a 57.2db noise level. A full 10db higher than the smaller, 6000BTU units.
Finally, the list above isn’t comprehensive. Frigidaire is noted as a very quiet unit, but the trade-off is price. Noise dampening comes at a higher cost to manufacture because of sound insulation built into the unit itself. Some manufacturers add a sound dampener around the air compressor, some do not. 3
The only real way to find out if your model has a sound blanket or baffle is to see under the case, usually by looking at the manual for that unit.
One other note: some manufacturers do not release noise level data. I’m looking at you, Amana, GE, Fedders…
Finding the right model
When shopping for a quiet window air conditioner, look for the dB rating for that unit. Not all manufacturers give out this information and others make it hard to find. In general, a manufacturer who produces a quiet product will mention the number – after all, it’s a selling point for them.
Frigidaire has a good reputation, but others will meet your needs as well. Importantly, you can do a search with the model number you are considering and look at reviews. Any overly loud units will generate complaints. You can also call the manufacturer or dealer and ask. As noise pollution becomes more of an issue, and as consumers become more aware of indoor noise levels, retailers are responding by giving actual dB numbers for comparison.
For a bedroom, consider a unit that has a sleep setting. These settings run a quieter, lower fan speed to mitigate noise levels. A smaller unit may be enough for a bedroom. The rule of thumb is “a quiet window air conditioner is a small window air conditioner”.
Units with a slide out chassis allow for the outer shell to be securely mounted separately, and then the “guts” put in place. This design can give a better, more solid mount which will reduce vibration and noise.
Finally, remember that mounting properly may mean as much or more than the dB level of the unit. Pay particular attention to window openings, mounting brackets and outside noise levels before you buy or install.