Often, after long-term operation of climatic equipment, owners notice that the air conditioner is noisy. There are many reasons for this. If noises appear when turning on the air conditioner, you should find the malfunction and eliminate it so as not to permanently damage the equipment. It is recommended to entrust diagnostics and repairs to the specialists of the service center.
Noise Standards
- 40 dB from 7.00 to 23.00;
- 30 dB from 23.00 to 7.00.
In order to determine these parameters, you must use special devices. If they are not there, it is not necessary to purchase only for these purposes, you can use comparative indicators. The tick of a home mechanical clock is approximately 30 dB. Normal conversation between people is 40 dB. If the air conditioner feels like it is operating with a higher sound, you need to respond to this by identifying the cause of the problem.
Causes of noise in the indoor unit
Usually, when the air conditioner is turned on, there is noise from the fan. It is a drum of blades that are mounted on a shaft. Over time, the sleeve bearings wear out, on which the impeller of the device rests. They become thinner, so the fan "sinks" and begins to touch the evaporator plates or the edges of the tray, which collects condensate.
It is impossible to solve this problem on your own. In the service center, the bearing bushings are replaced with new ones, and sometimes the entire impeller, if shaft wear has become critical.
Another reason for the appearance of noise is associated with the imbalance of the fan due to the formation of dirt on the blades. The impeller vibrates against nearby parts. Sometimes the balance weight jumps off its shaft, which also leads to vibrations. That is why manufacturers recommend once a year to inspect the indoor unit for the appearance of dirt deposits, especially on the fan.
Another source of noisy operation of the indoor unit of the split system is the fan motor. An interturn closure of the windings occurs in it.
The noise can be caused by a step-down transformer, which reduces the mains voltage from 220 volts to 24 volts. This voltage supplies the electronic control plate of the split system. The transformer is audible only when the air conditioner is off. The sound is not strong, no one pays attention to it during the day, but it is heard well at night. The problem will be solved by replacing the device. If the transformer burns out, you will have to turn off the air conditioner by pulling out the plug.
Another reason is the drainage pump, which drains the condensate collected in the tray under the evaporator. This small device works very quietly and for a long time. If the service life is exhausted, it begins to crack, it must be replaced with a new one.
Causes of noise in the outdoor unit
The outdoor unit of the split-system is equipped with:
- compressor,
- fan,
- capacitor,
- TRV.
Most often, the compressor and the fan blowing over the condenser are noisy. These two instruments have moving parts that wear out. But there are other reasons as well.
- lack of oil in the crankcase of the device - you need to top up;
- reducing the resistance of the stator windings;
- wear of parts - replace them or the compressor completely.
It is not possible to determine the low resistance of the starter windings on your own; for this, a special substance is used, which is poured into the crankcase with oil. It reacts to an acidic environment that destroys the winding insulation. An acidic environment inside the compressor arises during its long-term operation due to the ingress of moisture. The reagent changes the color of the oil, which confirms the concern. In this case, it is necessary to repair the compressor, as the windings will soon burn out.
Fans have the same problem - bearing wear. The impeller sags and starts to touch the protective grill located at the back, or the bottom of the housing. The most dangerous thing is when the blades of the device touch the capacitor. This can lead to pipe defects and refrigerant leakage.
If the split system is operated in winter, a large amount of ice accumulates in the sump under the fan, which is formed by freezing condensate. The fan blades can touch the fan and cause abnormal noise.
The outdoor unit is usually suspended by weight and attached to brackets. Vibration isolation pads made of rubber are placed between them and the vehicle body. Over time, they fail: they crack and burst. The steel case of the outdoor unit starts to rest against the brackets. During the operation of the fan and compressor, vibrations are created, the case begins to knock.
Sometimes the brackets themselves begin to knock on the wall if the fasteners are loose - usually metal dowels that are inserted into holes made in the wall with a puncher. The knock appears due to the vibration of the device. The problem is solved by drilling new holes and fixing in a new place.
Cheap air conditioners do not always tighten the fasteners to the end. For example, the rear grill of the outdoor unit just starts knocking on the body. Before installing the air conditioner, it is recommended to check all joints of parts and parts for their exact installation and tightening.
Sometimes people are alarmed by the noise of the wind when the household air conditioner is turned off. The reason is in the drainage channel that goes out into the street. If the wind is strong, some of the air flow is blown into the open end tube and the air conditioner hums. This happens with air conditioners installed on the upper floors. It is not always possible to solve the problem.
Testimonials
Irina Mukhina, Smolensk
We bought a split system in the spring. Have tried it, it works well. Of course, there is no need to include it at such a time. But at night he suddenly began to whistle. And it sounds like the wind is blowing. They themselves could not find anything, they called the master from the service center. He immediately said that the drain hose was whistling. As if the wind blows into it. He did it very simply - he put a piece of sponge into the hose from the street. Everything is calm now.
Marat, Kazan
Strange, but after five years of operation, the air conditioner in my house is buzzing. And the noise is incomprehensible with a thud. I myself am not friends with technology, so I called the master. He opened the panel that is inside the room. The horror, it turns out that the entire heat exchanger and the fan are overgrown with mud. The foreman explained that there was an imbalance in the fan, the bearings were loose. So he knocks on the evaporator. He said that I called on time. A little more, and instead of cleaning, I would have to purchase expensive spare parts.
