Often, after long-term operation of HVAC equipment, owners notice that the air conditioning is noisy. There are many reasons for this. If there are noises when you turn on the air conditioner, you should find the malfunction and eliminate it, so as not to permanently disable the equipment. Diagnostics and repairs are recommended to be entrusted to service center specialists.
Noise regulations
Certain norms of noise reproduction are presented to the operation of air conditioners:
- 40 dB from 7.00 to 23.00;
- 30 dB from 23.00 to 7.00.
In order to determine these parameters, it is necessary to use special devices. If they are not, it is not necessary to purchase only for these purposes, you can use comparative indicators. The ticking of a home mechanical watch is approximately 30 dB. Normal conversation between people is 40 dB. If it feels like the air conditioner is working with a higher sound, you need to respond to this, identifying the cause of the malfunction.
Causes of noise in the indoor unit
Usually, when you turn on the air conditioner, noise appears due to the fan. It is a drum of blades that are mounted on a shaft. Over time, the sliding bearings on which the impeller of the device rests wear out. They become thinner, so the fan “sags” and begins to touch the evaporator plates or the edges of the tray into which condensate is collected.
Wear of the bearings also leads to vibration of the fan impeller. When it rotates, not just a knock is heard on neighboring parts, the entire indoor unit begins to vibrate, hitting the surface of the wall to which it is attached.
It is impossible to solve this problem yourself. In the service center, the bearing bushings are replaced with new, and sometimes the entire impeller, if shaft wear has become critical.
Another reason for the appearance of noise is due to the imbalance of the fan due to the formation of dirt on the blades. The impeller begins to vibrate, striking against nearby parts. Sometimes a balancing 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 winding closure 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 is used to feed the electronic control board split system. The transformer is heard only when the air conditioner is turned 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 the plug from the outlet.
Another reason is the drainage pump, with the help of which the condensate collected in the tray under the evaporator is discharged. This small device works very quietly and for a long time. If the operational resource is exhausted, it begins to crack, it is necessary to replace it with a new one.
Causes of noise in the outdoor unit
In the outdoor unit of the split system are installed:
- compressor,
- fan,
- capacitor,
- TRV.
Most often, the compressor and the fan, which blows around the condenser, are noisy. These two devices have moving parts that wear out. But there are other reasons.
When the air conditioning compressor starts to make noise, there are several options for a malfunction:
- lack of oil in the crankcase of the device - you need to add;
- reduction of stator winding resistance;
- parts wear - replace them or the compressor completely.
It is not possible to determine the low resistance of the starter windings on their own, for this they use a special substance that is poured into the crankcase with oil. It reacts to an acidic environment that destroys the insulation of the winding. The acidic environment inside the compressor occurs during its long operation due to the ingress of moisture. The reagent changes the color of the oil, which confirms the concerns. In this case, compressor repair is necessary, since the windings will soon burn out.
The fans have the same problem - bearing wear. The impeller sags and begins to touch the protective grill located at the rear, or the bottom of the casing. The most dangerous thing is when the appliance blades touch the capacitor. This can lead to defects in the pipes and refrigerant leakage.
If the split system is operated in winter, a large amount of ice is collected in the pan under the fan, which is formed by freezing of condensate. The fan blades can touch it and cause extraneous noise.
The external unit is usually mounted on a weight and attached to the brackets. Between them and the body of the equipment vibration-proof gaskets made of rubber are laid. Over time, they fail: they crack and burst. The steel case of the external unit begins to abut against the brackets. During the operation of the fan and compressor, vibrations are created, the body begins to knock.
Sometimes the brackets themselves begin to knock on the wall if fasteners are loosened - usually metal dowels that are inserted into the holes made in the wall by a perforator. A knock appears due to the vibration of the device. The problem is solved by drilling new holes and fixing in a new place.
For cheap air conditioners, fasteners are not always tightened to the end. For example, the rear grille of the outdoor unit begins to simply knock on the body. Before installing the air conditioner, it is recommended to check all the joints of parts and parts for their exact installation and tightening.
Sometimes people are disturbed by the sound of the wind when the domestic air conditioner is turned off. The reason is in the drainage channel, which is displayed on the street. If the wind is strong, part of the air flow blows into the tube with an open end and the air conditioner buzzes. This happens with air conditioners installed on the upper floors. Solving a problem is not always possible.
Reviews
Irina Mukhina, Smolensk
Bought a spring split system. Tested, works well. Of course, it is not necessary to include it at such a time. But at night he suddenly began to whistle. And it sounds like the wind is blowing. They could not find anything, they called the masters from the service center. He immediately said that the drainage hose was whistling. As if the wind blows into it. He acted very simply - thrust a piece of sponge into the hose from the street. Now everything is calm.
Marat, Kazan
Strange, but after five years of operation, the air conditioning buzzes in my house. And the noise is incomprehensible with a knock. I myself am not friends with technology, so I called the master. He opened the panel which is inside the room. Horror, it turns out the whole heat exchanger and fan are overgrown with dirt. The master explained that the fan was unbalanced, the bearings loose. So he knocks on the evaporator. He said that on time I called. A little more and would have instead of cleaning to purchase expensive parts.
