Why does an air conditioner make a noise?
Indoor unit noise
A noise of an air conditioner usually appears after several years of operation with no service maintenance or even if it was carried out.
However, an unusual noise may also appear straight after the mounting of a split-system.
It is very important to determine the source of a noise correctly. After this, if you know a reason, it would be much easier to eliminate an unpleasant noise.
- fan bearing
- you can hear a clatter, a fan stops immediately after a shutdown, rotates with a slight effort
- interference with structural components
- usually occurs with old air conditioners because of the warping or deformation of plastics
- interference with ice
- detailed causes of ice formation and information on its removal are described in the article
Buzzing when off
- a buzzing is not loud, but prevents from sleeping
- it is widespread among cheap Chinese air conditioners
- the problem is solved by the replacement of a power supply transformer
Hissing when switching on
- the reason is coolant flotation in the tubes of an air conditioner
- it appears during constraints and when tubes are bent
- it is also observed when the intracavities of tubes are clogged
- may occur after the mounting of secondhand air conditioners
Air conditioner vibration
- sometimes an air conditioner can vibrate heavily, almost falling from a wall mounting
- the reason is the unbalance of a fan propeller
- a balance weight can fall off (as on an auto’s web of wheel)
- a more frequent reason is the intense dirtiness of a propeller. An unbalance is caused by either non-uniform dirtiness lengthwise of a propeller or falling of a dirt piece from a small area.
Drainage pump noise
- a drainage pump starts to rattle after its breakdown. In this case, cleaning or replacement of a pump is needed
- rattle will also occur after the lengthy downtime of an air conditioner because a pump rattles when operating in a dry condition. After some time, a rattle will be over
Outdoor unit noise
Since an outdoor unit is mounted near an indoor unit and usually outside a window, its noise causes a disturbance not only for the conditioner’s owner, but also for his neighbors, especially at night.
Outdoor unit noise reasons
No vibration absorbing rubber strips
- vibration absorbers are located between the brackets and feet of an air conditioner
- they reduce a vibration transfer from an air conditioner to a wall
Bolts of mountings brackets adjoin the metal mountings of a reinforced concrete wall
- it feels like a wall vibrates
- you can eliminate this problem by drilling holes in another place (near the previous place) and shifting the mountings there
Worn-out state of a compressor
- after many years of service and the lack of maintenance, a compressor may cause noise and vibration
- the interference with a grille and foreign objects occurs frequently
- the interference with ice may occur when working in a heating mode
- insignificant sound from structural components
- cheap conditioners often have vibrating structural components, including doors and grilles
- the problem is usually solved by the removal or placing of a sealer
- don’t be afraid to remove non-functional elements because they serve only for decorative purposes and manufactures usually save on them
We have explored the main reasons of noise from conditioners and the ways to eliminate it. But you have to remember that equipment after longstanding operation won’t work as new equipment, especially if plastic is a basic material of a conditioner’s case.