Which is thicker suction or liquid line?

The suction line is generally thicker than the liquid line in a refrigeration or air conditioning system. This is because the suction line carries low-pressure vapor from the evaporator to the compressor, requiring a larger diameter to accommodate the gas flow. In contrast, the liquid line transports high-pressure liquid refrigerant from the condenser to the expansion device, necessitating a smaller diameter. This design helps optimize efficiency and manage pressure differences in the system.