Should both lines be cold on a mini split?

Answered by Jason Smith

Both the liquid and suction lines should be cold on a mini-split system. The liquid line carries the refrigerant from the outdoor unit to the indoor unit, while the suction line carries the refrigerant back to the outdoor unit.

In the cooling mode, the refrigerant in the liquid line is in a high-pressure, high-temperature state after being compressed by the outdoor unit’s compressor. As the refrigerant travels through the liquid line, it releases heat to the surrounding air and begins to cool down. This cooling process causes the liquid line to become cold to the touch.

On the other hand, the suction line carries the low-pressure, low-temperature refrigerant back to the outdoor unit. As the refrigerant absorbs heat from the indoor air, it warms up and enters the suction line as a gas. The suction line is insulated to prevent condensation and maintain the temperature of the refrigerant, which helps to maintain its efficiency.

Insulating both the liquid and suction lines is important for several reasons. Firstly, it helps to prevent condensation on the lines, which can lead to water damage and reduce the efficiency of the system. Additionally, insulation helps to maintain the temperature of the refrigerant, preventing heat gain or loss during transit. This ensures that the system operates at its optimum efficiency and provides effective cooling.

When it comes to Samsung mini-split systems, it’s worth noting that the expansion device(s) are located in the outdoor unit. This means that in the cooling mode, the refrigerant in the liquid line has already gone through the expansion process and is in an expanded gas state. As a result, the liquid line will sweat and become cold to the touch.

It is important to insulate both the liquid and suction lines on a mini-split system to prevent condensation, maintain the temperature of the refrigerant, and ensure efficient operation. The liquid line will be cold to the touch in the cooling mode, as it carries the expanded gas refrigerant from the outdoor unit to the indoor unit.