When a refrigerator is turned on, it goes through a process called the refrigeration cycle to cool its interior and maintain a low temperature. During this cycle, various components and mechanisms operate to transfer heat from inside the refrigerator to the outside environment.
The loud noises you hear when a refrigerator is turned on are typically caused by the following components:
Compressor: The compressor is a crucial part of the refrigeration system. It is responsible for compressing the refrigerant gas, raising its pressure and temperature. When the compressor starts, it creates a sudden increase in pressure, which can lead to a loud humming or buzzing noise. As the compressor runs continuously, the noise may become less noticeable, especially in modern, quieter refrigerator models.
Evaporator Fan: Inside the refrigerator, there is an evaporator that cools the air by absorbing heat. An evaporator fan helps circulate the cold air to maintain a consistent temperature throughout the fridge. When the refrigerator is turned on, the fan may start at a higher speed, generating more noise. As the desired temperature is reached and the fan adjusts, the noise reduces.
Defrost Cycle: Refrigerators have a defrost cycle that helps prevent ice buildup on the evaporator coils. During the defrost cycle, a heating element turns on to melt the accumulated ice, and water drips into a pan at the bottom of the fridge. The sizzling or dripping sounds during the defrost cycle may be noticeable but are typically brief.
After some time, once the refrigerator reaches its target temperature and the cooling process stabilizes, the compressor and other components may cycle on and off to maintain the desired temperature. When the refrigerator is in this steady-state mode, the noises are significantly reduced or may even stop altogether.
Moreover, newer refrigerator models are designed with improved insulation and more efficient components, making them quieter during operation. If your refrigerator continues to make loud or unusual noises even after the initial startup period, it could be a sign of a mechanical issue, and it might be worth having it checked by a professional technician. Regular maintenance and cleaning of the coils and fan can also help keep your refrigerator running smoothly and quietly.