Constant humming in the kitchen often becomes a background irritant that we stop noticing until it crosses certain boundaries. When the refrigerator starts to sound like a plane taking off or makes strange clicking noises in the middle of the night, questions arise about whether such indicators are acceptable. An accurate determination of the sound pressure level is necessary not only for the comfort of residents, but also to substantiate claims against the manufacturer or service department.
Before sounding the alarm and calling a technician, it is necessary to objectively assess the situation. Many users confuse normal compressor operating hum with signs of trouble, while others ignore truly dangerous vibrations. The correct approach to diagnostics will save time and nerves, as well as understand whether complex repairs are required or simple adjustments are sufficient.
In this article we will look at what instruments are used to measure decibels, how to distinguish natural sounds of equipment operation from anomalies, and what to do if the readings exceed acceptable standards. You will learn how to prepare a room for the test and what factors can distort the measurement results.
Noise standards for modern refrigeration equipment
Modern manufacturers strive for maximum noiselessness, but it is impossible to make the equipment completely inaudible due to the physical processes of refrigerant compression.
Normative indicators directly depend on the type of compressor and the design of the unit. For most standard models on the market, a range of 35 to 45 dB is considered acceptable. This is a level comparable to a quiet whisper or rustling of leaves, which should not interfere with daytime rest.
If the technical specifications Bosch or Liebherr state a value of 38 dB, but in practice you hear a clear buzzing, this is a reason to check. However, it is worth considering that in an empty chamber, sound can propagate differently than in a chamber filled with products.
There is a division of equipment according to energy efficiency classes and type of cooling, which affects acoustic comfort. Inverter models operate much quieter, since the compressor does not turn off completely, but only changes speed, eliminating sudden starting currents and sounds.
The table below shows average values for various types of equipment:
| Refrigerator type | Average noise level (dB) | Maximum permissible (dB) | Sound character |
|---|---|---|---|
| Single compressor (No Frost) | 39-42 | 47 | Uniform hum, periodic clicks |
| Two compressor | 40-44 | 48 | More pronounced hum, operation of two motors |
| Inverter | 30-36 | 42 | Quiet hiss, low-frequency hum |
| Built-in (in a niche) | 35-39 | 45 | Muffled, depends on the furniture |
It is important to understand that measurements are carried out in special acoustic chambers, so at home the numbers may differ by several decibels upward.
⚠️ Attention: If the noise level of your device consistently exceeds 50 dB, this is considered a violation of quality standards for household appliances and may indicate a serious malfunction of the components.
Necessary tools for measuring decibels
To obtain reliable data, it is not enough just to listen - the human ear subjectively evaluates loudness. You will need specialized equipment that converts sound vibrations into digital values.
The main device is Sound Meter. This device is equipped with a microphone and a display showing the current sound pressure level. Professional models are expensive, but for a one-time check you can use high-quality household analogs or even a smartphone with a calibrated application.
When using a smartphone Therefore, the readings may have an error of up to 3-5 dB.
- 📱 Mobile application: Install proven software, for example, "Sound Meter" or "Decibel" X", having previously calibrated it against a reference source.
- 🎙️ Digital sound level meter: Portable device with a measurement range from 30 to 130 dB, providing high accuracy.
- 📏 Tape measure: Necessary to maintain the standard distance from sound source to the microphone (usually 1 meter).
- 🔇 Source of silence: Make sure that the TV and radio in the room are turned off and the windows are closed to minimize background noise.
Before starting measurements, allow the device to warm up (if this professional sound level meter) and check the battery charge. Unstable power supply can lead to jumps in the readings on the screen.
Step-by-step instructions: how to correctly measure noise
The measurement procedure requires compliance with certain conditions so that the results can be compared with the passport data. First of all, you need to prepare the room: close the windows and doors, turn off all sound sources, including ventilation and air conditioners.
The refrigerator should operate normally. Do not open the doors during measurement as this will start the refrigeration cycle and change the way the compressor operates. Wait 15-20 minutes after the last opening of the chamber for the system to stabilize.
☑️ Preparing for noise measurement
Place a sound level meter or smartphone at a distance of 1 meter from the front panel of the refrigerator at a height of 1.5 meters from the floor. This is the standard height of a person's ears in a standing position. If the refrigerator is built into a niche, measurements are taken in the center of the open space in front of the niche.
Record the maximum and minimum values during 5-10 minutes of the cycle. Pay special attention to the moments of turning the motor on and off, as well as the operation of the system fans No Frost.
Repeat the procedure several times at different times of the day to eliminate the influence of external factors, such as the noise of an elevator or traffic outside the window. The arithmetic average of several measurements will give the most objective picture.
Analysis of the causes of increased sound pressure
If measurements show exceeding the norm, it is necessary to classify the type of sound. The nature of the noise often indicates which part requires attention. The hum can be mechanical, aerodynamic, or caused by vibration.
Mechanical wear of compressor or fan bearings often manifests itself in the form of an increasing howl or metallic clanging. Over time, the lubricant dries out and the friction of the parts increases, which leads to an increase in operating volume.
Vibration of the housing can be transmitted to the floor or nearby objects. Even a perfectly running motor will sound loud if the refrigerator touches a wall or cabinet. Check the gap between the back wall and the furniture - it should be at least 5-7 cm.
- 🔊 Loud start: A sharp sound when the compressor is turned on may indicate problems with the starting relay or loose motor mounts.
- 💨 Air whistling: Characteristic of the No Frost system and indicates icing air ducts or damper malfunction.
- 💧 Gurgling: The sound of refrigerant flowing is normal, but if it is too loud, there may be an air lock in the system.
- 🔨 Knock: Occurs frequently due to the fact that the internal shelves or bottles touch each other during vibration.
In some cases, the cause of the noise is not the unit itself, but the place where it is installed. An uneven floor causes the refrigerator to warp, which leads to an imbalance in the motor rotor.
⚠️ Attention: If you hear a loud pop or cracking sound, immediately unplug the appliance. This may indicate an electric arc breakdown or destruction of internal components.
Influence of room temperature
In hot weather (above +30°C), the compressor works almost non-stop, trying to maintain cold. In such conditions, the noise level will always be higher than rated, since the engine is operating at the limit of its capabilities.
Do-it-yourself methods for reducing noise levels
It is not always necessary to call a technician to fix a problem. Many sources of excess sound can be eliminated yourself using simple control and isolation techniques.
The first step should always be adjusting the supports. Using a spirit level, make sure the refrigerator is level. Tighten the front legs so that the doors close on their own with a slight push, and the body does not wobble.
Check all internal elements: remove shelves, containers and bottles to prevent them from rattling. Sometimes it's enough just to adjust the pots in the freezer to make the annoying ringing disappear.
If the problem is vibration transmitted to the floor, use anti-vibration pads under the feet. They are made of dense rubber and effectively dampen vibrations, preventing them from spreading across the floors.
For models with the No Frost system, periodic noise may be associated with ice freezing on the fan. In this case, completely defrosting the unit for 24 hours with the doors open will help.
When professional repairs are necessary
There are situations when independent actions are not only useless, but also dangerous. If, after all checks and adjustments, the noise level remains high, and the nature of the sound indicates a mechanical breakdown, professional intervention is required.
Replacing a compressor or fan motor is a complex operation that requires evacuation of the system and charging of refrigerant. An attempt at self-repair in this case will lead to loss of warranty and possible damage to the equipment.
It is also worth contacting the service center if the noise is accompanied by other symptoms: insufficient cooling, the appearance of ice in unintended places or a burning smell.
- 🛠️ Replacing shock absorbers: If the motor mounts are worn out, the technician will install new dampers, which will return silence.
- ❄️ Defrosting the system: A specialist can clean the drainage and remove ice plugs that cause whistling.
- ⚙️ Electronics diagnostics: Checking the control board to ensure the correct voltage supply to compressor.
Remember that timely contacting a service center is often cheaper than replacing the entire unit due to ignoring the first signs of a malfunction.
Is it possible to measure the noise of a refrigerator without special instruments?
No way to accurately measure it in decibels. However, you can conduct a comparison test: turn on the vacuum cleaner (about 70-80 dB) and compare the volume. If the refrigerator sounds louder than a normal conversation (about 60 dB), this is a clear sign of a problem.
Why is the new refrigerator noisier than the old one?
Modern models often use more powerful compressors and No Frost air circulation systems, which create a constant background hum, unlike older models, which hummed rarely but loudly. There may also be a “fresh memory” effect when you simply began to pay more attention to it.
Does the amount of food affect the noise level?
Yes, a full refrigerator is quieter. The products act as acoustic absorbers, dampening vibrations and echoes within the chambers. An empty unit can resonate, enhancing the sound of a running motor.
Is it normal for the refrigerator to gurgle after it is turned off?
Yes, this is absolutely normal. The sound of liquid (refrigerant) flowing in the pipes may persist for several minutes after the compressor stops. This indicates the correct operation of the circulation system.