Modern household appliances are becoming quieter, but completely silent refrigerators do not yet exist. Owners often become concerned when they hear new noises, humming or periodic gurgling, not knowing whether this is a sign of a breakdown or normal operation of the equipment. Understanding what kind of sound a refrigerator should havehelps to avoid unnecessary calls to the technician and save on repairs.
The sound background of a working unit consists of many factors: motor vibration, refrigerant flow through the pipes, operation of fans and even clicks of the thermostat. It is important to learn to differentiate these acoustic manifestations. If you hear a smooth, monotonous hum that fades in and out depending on the cooling cycle, most likely there is nothing wrong with your equipment. However, sudden changes in the acoustic picture can signal serious problems with compressor or the heat removal system.
In this article we will analyze in detail the physics of the sounds made by refrigeration equipment and learn to distinguish harmless phenomena from the harbingers of expensive repairs. You will find out why you can sometimes hear the sound of running water, what a loud bang means when turned off, and how the noise level depends on the type of engine installed. The critical noise threshold for modern models is considered to be above 40 dB in a quiet room, which requires an immediate check of the installation and technical condition.
Physics of operating noise: why the engine hums
The main source of sound in any refrigerator is compressor. This is the heart of the system, which compresses the refrigerant and forces it to circulate throughout the circuit. Older models had piston engines, which produced quite loud, low-frequency hums and noticeable vibration. Modern manufacturers are increasingly using inverter compressorsworking on the principle of smooth changes in power, rather than constant switching on and off.
The normal sound for a running motor is considered to be a smooth, low-frequency hum. It may be barely noticeable during the day, but becomes more obvious at night when the apartment is quiet. The intensity of the hum directly depends on the load: immediately after opening the door or loading warm food, the motor begins to work more actively, and the sound intensifies. This is a normal situation that does not require intervention.
However, there are nuances that may alert the owner. If the hum is accompanied by rattling or turns into a low howl, you should pay attention to the engine mount. Often vibration is transmitted to the body or nearby objects, creating resonance. It is also worth checking whether the system tubes are touching each other or the walls of the cabinet, since they can vibrate and knock when the motor is running.
⚠️ Attention: If the hum of the motor becomes intermittent, accompanied by a metallic clang or a sharp change in tone, immediately unplug the device from the network. This may indicate a wedge of the piston group or destruction of the shaft bearings.
Sounds of freon circulation: gurgling and overflowing
One of the most common questions asked by owners of new equipment: why does the refrigerator make sounds similar to water pouring or gurgling? The answer lies in the physics of phase transitions refrigerant. Inside the system, freon constantly changes its state of aggregation from gas to liquid and back. This process is accompanied by a characteristic acoustic effect.
The sound of flowing liquid is most often heard immediately after the compressor stops or during moments of its quiet operation. This is normal, as the pressure in the system equalizes and the remaining liquid refrigerant flows into certain areas of the circuit. In models with the system No Frost these sounds can be heard a little more clearly due to the design features of the evaporator and the presence of additional channels.
Sometimes users confuse the sound of freon circulation with a leak. It is important to understand: if the floor is dry and no puddles form inside the chamber outside the drainage hole, then the “murmuring” is absolutely safe. It indicates that the system is sealed and the refrigerant moves freely through the tubes, performing its function.
Clicks, crackles and pops: operation of automation and temperature compensation
Periodic clicks are another type of sound that should not cause panic. Their source is most often thermostat or the starting relay. When the temperature inside the chamber reaches the set value, the thermostat opens the circuit and a characteristic click is heard. A similar sound occurs when the motor is turned on.
In addition to electrical clicks, quiet crackling or single pops are often heard in refrigerators. This phenomenon is called thermal compensation. The materials from which the inner plastic container and the outer walls of the cabinet are made have different coefficients of thermal expansion. When there is a sudden change in temperature (for example, after a defrost cycle or intensive operation of the motor), plastic and metal expand or contract, making sounds.
Crackling is especially often heard in new refrigerators or after prolonged defrosting. Over time, as the materials wear in, these sounds may become less noticeable, but will not disappear completely. This is a design feature, not an assembly defect. If the crackling becomes very loud, like gunshots, or is accompanied by a burning smell, you need to check the electrical contacts.
- 🔊 Rhythmic clicks every 30-60 minutes - normal operation of the thermostat.
- 🔊 Single cotton when the engine stops - pressure equalization in the system.
- 🔊 Quiet crackling plastic - thermal expansion of the body materials.
Fan noise in the No Frost system
Owners of refrigerators with the system No Frost good are familiar with the constant background noise that fans make. Unlike static models, where the cold is distributed naturally, here the air is forced through the chambers. This creates a continuous flow of air that sounds like a quiet whistle or a uniform hum.
The intensity of the fan noise depends on its location. On some models it is located at the top of the freezer, on others it is behind the back panel. If the noise becomes shrill, whistling, or begins to resemble a howl, this may indicate frosting of the blades or wear of the fan motor bearing.
It is important to distinguish between operating airflow hum and mechanical noise. The working sound is smooth and monotonous. A mechanical defect manifests itself in the form of rattling, knocking or intermittent humming. Often the cause of extraneous sounds is ice that builds up on the evaporator and begins to touch the fan blades when rotating.
Why does the fan start to make noise in winter?
In winter, when the humidity in the room is low and the door opens often, a lot of moisture gets into the chamber. It settles on the evaporator and, if the defrosting system is insufficiently efficient, it turns into an ice crust that interferes with the rotation of the fan.
Comparative table of noise levels
To objectively assess the situation, it is useful to understand what sound pressure levels are considered normal for different types of equipment. Manufacturers always indicate this parameter in the technical data sheet, but actual measurements may differ depending on operating conditions.
| Equipment type | Normal level (dB) | Critical level (dB) | Sound character |
|---|---|---|---|
| Old refrigerator (compressor) | 38 - 42 | > 50 | Low hum, vibration |
| Modern No Frost | 35 - 39 | > 45 | Hum + wind noise |
| Inverter model | 30 - 36 | > 42 | Barely audible hum |
| Built-in refrigerator | 32 - 38 | > 45 | Depends on the furniture |
It is worth considering that sound pressure is measured at a distance of 1 meter from the source. Closer to the ear, the sound will always seem louder. Additionally, an empty kitchen with tiled floors and smooth walls creates echoes, increasing the perceived noise. The presence of carpets, curtains and upholstered furniture significantly reduces the level of acoustic discomfort.
Diagnostics of faults by sound
The ability to “listen” to your refrigerator can save you from losing food and expensive repairs. There are several sound markers that clearly indicate the need to call a specialist. Ignoring these signals can lead to complete failure of the compressor.
One of the most dangerous situations is the operation of the motor without shutdowns, accompanied by an excessively loud, strained hum. This could mean a loss of compressor performance or a freon leak, causing the motor to try to compensate for the lack of cold by operating at maximum capacity. A sound similar to a metallic grinding or knocking sound is also dangerous.
- 🛑 Loud knocking when starting - a problem with the start relay or compressor.
- 🛑 Shrill whistling - freon leak or fan malfunction.
- 🛑 Gurgling with hissing (constant) - possible depressurization of the circuit.
⚠️ Attention: If you hear the sound of breaking glass or strong vibration that is transmitted to the floor, check to see if a glass shelf or bottle has fallen inside the chamber. Foreign objects may resonate with the vibration of the motor.
☑️ Diagnosis of refrigerator noise
How to reduce the noise level: practical tips
Even a working refrigerator can make more noise than expected due to improper installation. First of all, check that the installation is horizontal. If the device is not level, the vibration of the motor is transmitted to the housing and intensified. Adjusting the legs is the simplest operation, which often solves the problem of hum.
The second important point is the distance to the walls and furniture. For normal air circulation and vibration damping, the refrigerator needs space. If it is close to a wall or cabinets, the sound will be reflected and amplified. Also check whether the pipes of the rear grille are touching each other.
For owners of equipment with the system No Frost regular defrosting is important. Even if the manufacturer states that there is no need to defrost, a preventive shutdown once a year will help remove ice build-up on the fan, which often causes howling and crackling.
The influence of the type of compressor on the acoustic comfort
When choosing new equipment, many people forget to pay attention to the type of compressor, but it is this that determines how quiet your refrigerator will be. Conventional linear compressors operate on the principle “turned on - worked at full capacity - turned off”. This creates a cyclical noise that appears and disappears.
Inverter models do not have this drawback. They turn on once and simply change the rotational power of the shaft depending on the need for cold. Due to the absence of constant starts and stops, such refrigerators operate much quieter and more evenly. The sound in them is more like a quiet hiss than a hum.
However, it is worth remembering that inverter systems are more complex and more sensitive to voltage drops in the network. For their quiet and durable operation, it is recommended to use a voltage stabilizer, especially in houses with an unstable electrical network.
Compressor service life
A conventional compressor is designed for approximately 10 years of operation with frequent switching cycles. An inverter, due to the absence of peak loads at start, can last 15-20 years, but requires higher quality electricity.
Why does a refrigerator make a sound similar to croaking or croaking?
Such strange sounds are most often produced by the defrosting system in No Frost models. When the heating element is heated, the ice melts and drips onto the hot surface, which can create sounds similar to croaking. This could also be the sound of plastic parts deforming when heated.
Is it normal if the refrigerator hums immediately after being plugged in?
Yes, this is absolutely normal. In the first minutes after switching on, the compressor operates at maximum power to quickly cool the chambers to the set temperature. It switches to this mode automatically.
Can the sound of a refrigerator change in winter?
Yes, in winter, when batteries are running in apartments and the air becomes dry, as well as when doors are opened frequently, the load on the system may change. In addition, cold air in the room affects the heat transfer of the condenser, which can change the way the motor operates.
What to do if the new refrigerator is noisier than the old one?
Modern refrigerators may sound different due to different body materials and the type of compressor. Give the equipment 2-3 days to “grind in.” If the noise does not subside and exceeds 40 dB, contact a service center for inspection.
Is high-frequency squeaking dangerous?
High-frequency squeaking is often produced by an inverter compressor or electronics unit. If the squeak is quiet and does not interfere, this is normal. If the sound is loud and increasing, this is a sign of a malfunction of the electronics or the throttle.