Refrigerators primarily run on alternating current (AC) rather than direct current (DC) due to historical reasons and the nature of electricity distribution.
Historical reasons: When refrigerators were first developed and became widely used in households, AC power was already the established standard for electricity distribution. The widespread adoption of AC power systems made it more practical to design and manufacture refrigerators that could directly plug into the existing electrical infrastructure.
Electricity distribution: The majority of electrical power generation and distribution systems around the world use AC. AC power can be easily transformed to different voltage levels, making it more efficient for long-distance transmission and distribution across power grids. This is not the case with DC, which requires more complex and costly transformation methods.
Motor operation: The compressor, which is a critical component in refrigerators responsible for circulating the refrigerant and maintaining the cooling process, typically requires an AC motor to function efficiently. AC motors are more straightforward in design, have higher starting torque, and are more suitable for heavy-duty applications like the compressor in a refrigerator.
However, it's worth noting that some modern appliances, including refrigerators, may use both AC and DC internally. For example, many refrigerators have electronic components that operate on low-voltage DC power. To accommodate this, they convert the incoming AC power to DC for these specific components. But for the main operation and motor function, AC power remains the primary source.